the ninth day of testimony of the trial of the former minneapolis police officer derek chauvin charged in the death of george floyd. the jury heard from critical care specialist doctor martin who by his own analysis determined it was a lack of oxygen that led to mr. floyd's death.

>> we are on the record and outside is the jury. mr. nelson, you wish to make a record. >> [inaudible] i will have you up there. >> yes, your honor. very briefly for purposes of it is my understanding that the state is intending to start calling its medical experts this morning. a lot of -- all of the experts ultimately rely on some degree on doctor baker's autopsy and his findings and that information. i don't have a problem calling mr. baker or doctor baker out of order for purposes of foundation, however, i just want to make sure that the record reflects the state does intend to call doctor baker. >> any objection to foundation is based on the purpose presentation that they will call doctor baker. >> correct, your honor.

>> yes, your honor, we intend to do so tomorrow. >> anything for the record before we bring back the jury?

>> [no audio] good morning, everybody. mr. blackwell. >> good morning, your honor, counsel, ladies and gentlemen. we will call the first with this this morning, doctor martin

tobin. do you swear or affirm underou penalty and perjury the testimony you are about to give will be the truth and nothing but the truth? >> i do. >> and doctor, if you wouldn't mind removing your mask for your testimony. and also, to make sure the microphone is properly placed we will have you state your full name. >> martin tobin.

>> mr. blackwell. >> good morning, doctor tobin. >> good morning, mr. blackwell. >> would you tell us your current employment? >> i'm a physician in pulmonary and critical care medicine. >> and whereabouts? >> in chicago and at loyola university school. >> and is the hospital a large facility? >> it used to be the largest va hospital in the country i think. it's now been superseded by one or two others. >> and you specialize in pulmonology? >> i specialize in the pulmonology and critical care medicine.. >> would you tell the jury what pulmonology is? >> pulmonology is the study of the lungs. it deals with all diseases that

affect the respiratory system, so the lungs, the chest wall. >> so, what are the various elements and components of the respiratory system, other than the lungs and chest wall? >> the respiratory system begins at the nose and the mouth and it goes down to the back of the throat, down to the windpipe out through the bronchial tubes, and then down at the bottom down to the air sacs. these are the small structures at the bottom where all of the gas exchange takes place or oxygen gets in and carbon dioxide is removed. >> so this is the system that we are getting oxygen into the body. >> correct. >> that is the prime purpose, t> get oxygen in. >> at heinz hospital, do you work in the intensive care unit? >> yes, i work in the medical intensive care unit. >> and that is considered critical care? >> same as critical care.

these words all have the same meaning. >> 's critical care different from emergency medicine? >> it's very different from emergency medicine. emergency is kind of the front door of the hospital in the triage area where you separate out where people need to go. where the critical care is where you take the very sickest people. >> what kind of patients do you see in the icu? >> in the icu, probably more than half the patients that are requiring mechanical ventilation, so they are on a respirator to help them with their breathing, and another substantial number will not be on a respirator, but their primary problems relate to their lungs so that might make up 70% or so. ..

>> i have been a physician three months short of 46 years. went to medical school in dublin ireland and took my degree there. blackwell: not the anybody noticed your accent. but are you from dublin? >> no. from a small village called fresh board in rural ireland. blackwell: what degrees do you hold. >> the irish equivalent of the american m.d. and then subsequently i have the md

through research. blackwell: you currently licensed? >> yes i am licensed in the state of illinois. in the past i was licensed in ireland and england and a number of us states and let them lapse the only place i am practicing is in illinois. blackwell: are you board-certified. >> yes. internal medicine, pulmonary medicine in critical pci care medicine. blackwell: you are still actively caring for patients. >> yes. taking care of patients in the icu last week and then i go straight back into the icu again when i get back. blackwell: how long you had a position that loyola. >> i been at loyola and heinz 32 years almost.

blackwell: before going to loyola were you practicing medicine somewhere else? >> i spent seven years at the university of texas at houston. blackwell: did you set up a sleep clinic in houston? picked that would've been in the early eighties i set up another very first sleep labs in the united states for evaluating patients with obstructive sleep apnea. blackwell: how does that fitat within your expertise? >> the problems with sleep, particularly those who snore duringht the nighttime they include their upper airway they could start breeding 500 or 600 times and i and a level of oxygen in their blood will go very low. the basic problem in sleep apnea is because the soft palate, the roof of your mouth is the hard palate then the

tiny down the back is the soft palate. that jams against the back of your throat and is occluded 500 times a night. for someone who has sleep apnea. blackwell: does that kind of research relate in this case. >> it is because obviously with sleep apnea the problem is at the back of the throat and as we can see in mr. floyd the problem of where the obstruction is occurring is in the hypopharynx again at the back of the throat. it has a lot of overlap to patients with sleep apnea. blackwell: will come back to the hypopharynx. are you engaged in medical research?

yes. >> yes. been doing medical research since the early eighties about 1981. blackwell: what type of research? >> all of my research is related basically to breathing. it is looking at breathing in patients with lung disease people who have lung disease that walk in the door to the clinic and those in the icu and particularly those who are require mechanical ventilation but then i do a lot of research that has absently nothing to do with clinical medicine just to know how people brief. blackwell: have you offered a textbook on ventilation? >> yes a large textbook on mechanical ventilation called the principles and practices of mechanical ventilation. blackwell: i'm showing the cover of your textbook here on the camera.

is this the book you are referring to? >> that's correct. blackwell: 1500 pages. >> correct. blackwell: are you familiar with the lancet medical journal? >> that is one of the top medical journals in the world. blackwell: does the lancet medical journal refer to this book as the bible of mechanical ventilation? >> yes. it has all of that. blackwell: have you authored other books? >ow yes. i think i have published eight or nine other books. blackwell: all relatedir to respiration respiratory failure? >> yes all different aspects of the lungs. blackwell: have you published articles and abstracts? >> yes i have. i lose count but i think i have published more than 750.

blackwell: new england journal of medicine? >> yes several articles. blackwell: journal ama? >> yes. blackwell: those two of the most respected medical journals in the world? >> they are for clinical work, yes. blackwell: heavy held editoral positions at medical journals? >> editor in chief of the journal the american journal of respiratory care and critical care medicine. that's for all long disease also the premier journal in the world for intensive care medicine. the official journal of the american thoracic society. blackwell: have you tied and lectured outside of illinois and texas? >> yes. blackwell: generally, where? >> all around the world. in more than 30 different countries around the world. the vast majority of states within thes united states.

blackwell: minnesota? i have lectured in minnesota. i have been in the mayo clinic several times as a lecturer. blackwell: we are given an award from the mayo clinic? >> yes. they give it out to one doctor every ten years and only to one doctor. it doesn't matter what specialty gynecology, neurology or whatever they just pick one personhe every ten years. blackwell: was at breathing in particular you are recognized? >> no just for my work as a researcher in clinical medicine. blackwell: have you published in basic science journals such as the journal of applied physiology? >> yes. and that wouldn't be directly related to medicine.

>> the jurors may not be understanding physiology. >> that is basically how the body works you want to know the science of how it works with a deeper understanding of the mechanisms that make the body does what it does. blackwell: within the field i of physiology is a focus or interest that you have? >>re primarily interested in breathing. with breathing how the brain regulates your breathing and sends signals down to the muscles that control your breathing, the diaphragm, rib cage and then how you expand your chest and overcome forces within your chest like resistance to get air moving in and out of your lungs. and then the particular forces that you generate in terms of

the pressures in your chest to enable breathing to occur with the ultimate purpose to get oxygen in and getting rid of carbonsi monoxide. blackwell: do you consider this a part of the study of medicine? >> not quite it is quite separate because more i the basic physiology it's more in the realm of math and physics. but it is applied all over to be a good doctor you need to have a good knowledge of science. the science part is separate from the medical part to try to hone down on the science as best as possible. blackwell: how long have you been working respiratory physiology? >> 1981. blackwell: what drew yout to the physiology of reading? >> because i was going into pulmonary i knew i spent five

years doing lung disease i just wanted to really know how you breathe and i wanted to come upwl with new knowledge because everybody thought they knew everything about breathing i want to find new stuff. blackwell: do you know of others in your field who have been studying respiratory physiology 46 years? >> no more than a handful or less of people who were still doing physiology at patient's bedside after 46 years. blackwell. blackwell: let's talk about your experience as serving as an expert. have you served as h an expert witness before? >> yes. blackwell: what types of cases?

>> practically all of them have been medical malpractice for both the plaintiff and the patient side and the defense for the physician side. blackwell: have you ever been involved in a criminal case? >> no. blackwell: have you testified in courte before? >> i have testified in court i don't keep track but i suspect about 50 times. blackwell: total ladies and gentlemen if you are getting paid for your time in this case. >> no i am not getting paid. blackwell: why is that? >> when i was asked to do the case, i thought i may have some knowledge that would be helpful to explain how mr. floyd died. since i have never done this type of work in this nature i decided i should not be paid. blackwell: did you volunteer to the state of minnesota or

did the state contact you? >> the state contacted me. blackwell: what you asked to do? >> to review the medical records related to the case this was from hennepin county and there were a number of interviews the people that are interviewed and primarily it was related to looking at a large number of different videos. but theou big part was i needed to read on the scientific background. blackwell: let's talk about your opinions with respect to this case. have you formed an opinion to a reasonable degree of medical certainty on the cause of mr. floyd's death? >> yes i have. blackwell: please tell the jury but those opinions are. >> mr. floyd died from a low

level of oxygen. this caused damage to his brain that we see and it also caused a pea arrhythmia that caused his heart to stop. blackwell: by pea you mean pulseless electrical activity. >> correct it is a particular form of an abnormal beat of the heart. blackwell: is this what some persons might refer to as asphyxia? >> it has been called dyslexia. to me that is not helpful. what we're really talking about is a low level of oxygen. some people talk about hypoxia is just the latin term meaning the low level of oxygen. all of this art other words for a phenomenon that is a low level of oxygen.

blackwell: have you formed an opinion to a reasonable degree of medical certainty as to what the cause is or was for the low level of oxygen in mr. floyd? >> yes i have. because of the low level of oxygen was shallow breathing. small breasts. small title volumes shallow breath that could not carry the air to his lungs down to the essential areas of the lungs i get oxygen into the blood to get rid of the carbon dioxide. that is the av ally at the bottom of the lungs. blackwell: doctor tobin using a short video with that help explain to the jurors how oxygen gets into the lungs and the body. >> can you describe what this

is? >> we are looking aty the lungs inside the body and we see here you can see the windpipe and the trachea going into the bronchial tubes and also the diaphragm at the bottom. and the diaphragm contracts. blackwell: the jurors cannot see it yet. >> i'm sorry. i apologize. blackwell: exhibit 950. please proceed weur can display it. >> youot can see the contraction of the diaphragm which is the pink area at the bottom air goes down through the windpipe proceeding to the bronchial tubes. then it will continue down the bronchial tube out to the air sacked which is the aveoli and

no these are the grape like structures at theth bottom this is where all the action occurs the oxygen goes across the air sacs and the sealed seat on - - co2 goes back out. that's everything in a very rapid video. blackwell: what happened in the case of mr. floyd that relates to the shallow breathing relating in his low oxygen? >> a number of forces that led to thehe size of his breath that became so small those higher-ups that are leading to that andng that leads to the shallow breath that he is turned brown on the street with handcuffs in place combined with the street and a knee on his neck and on his

back down his side. all four forces are ultimately going to result in the low title volume which gives the shallow breath that we saw here. the air willh not be able to reach the air sacs we just saw on the video where oxygen is exchanged in carbon dioxide is removed. blackwell: is there a concept known as dead space? >> yes. blackwell: how does that v relate? blackwell: think back to the clusters of grapes you saw the blood vessels around the alveoli up through there is dead space. as you breathe through your nose and mouth into your windpipe through the bronchial tubes radiating out to reach the air sacs up and tell the nurse on - - air sacs is dead

space because noan oxygen can get across the bronchial tubes. no carbon oxide can get across it. the only place that gets across one - - across are the grape like structures everything before that is dead space. blackwell: you mentioned several reasons for mr. floyd's low oxygen. i went to capture those for the jury. you mention handcuffs and the street. >> correct. blackwell: you mentioned neon the neck. >> yes. blackwell: prone position. >> yes and then the knee on

the back, arm, side. >> those are the four. blackwell: before we talk about each of these might it be helpful to explain to the jury for them to see the relative positioning of mr. floyd's body while he was subdued on the ground. >> that wouldho be helpful. blackwell: did you assistant illustration to show on the ground of the officers position? >> yes. blackwell: exhibit 949. tell us what it is.

>> i watched the videos and certain segments hundreds of times. it's difficult to get the overall view where everybody is positioned because you see different videos from different angles. the artist has taken all the different videos here and combined them into one moment in time. also he would remove the police vehicles you can get a better view like a birds eye view of where mr. floyd is lying and where the officers are positioned in relationship to mr. floyd. blackwell: the purpose of this to show relative positions of the officers? >> correct. blackwell: exhibit 949. >> received. blackwell: at what point in

time? >> it is a particular point in time. i don't o remember the exact minute or second at the top of my head. [sidebar] blackwell: let's walk through exhibit 949 and tell us what we are seeing. >> the car is being rotated.

you can see officer chauvin andd officer keung and officer lane at his feet. you can see how the car has been rotated no it has been removed. so you can see how they are positioned at different points in terms with officer chauvin the left of the on the neck. the right knee on mr. floyd's arm and chest. then you can see here the officer lane holding his legs and officer keung with the knee on the torso. blackwell: this is a snapshot in time as you told us. did the officers positions change over time? >> yes the officers positions changed overn time also the position of mr. floyd changed himself in these becomere relevant in how we evaluate.

blackwell: is it something you factored into your analysis? >> yes. blackwell: did you consider where mr. chauvin left knee was? >> yes. with officer chauvin is virtually on the neck for the vast majority of the time. blackwell: vastma majority. >> more than 90 percent of the time. there certain times iterta is difficult because you don't get a good view of where it is. for example i know that officer chauvin right knee is on his back 57 percent of the time. i cannot say for the 43 percent i don't get a good view of exactly where it is. blackwell: did you focus on

the first five minutes three seconds? >> yes. that is up to the time that we see evidence of brain injury. blackwell: if mr. chauvin right knee was on his back from time to time and at other times it was placed where? >> on his arm and then into mr. floyd's left chest. if you are making a distinction if the knee is on the cheste, per se or whether it is on the left arm from the left chest from the point of view of breathing the effects are extremely similar. blackwell: let's turn to number one.

blackwell: let's turn back to the notes the number one was written down for the reasons of mr. floyd's low auction want us oxygen was handcuffed on the street. >> yes. blackwell: doctor tobin first how the various mechanisms, the four that you discussed, handcuffs company on the net, prone position and knee on the back and arm and side how do those fall into your worke of respiratory physiology or clinical medicine? >> they don't have a lot to do with clinical medicine but directly related to my work and physiology in understanding the forces the

body has to cope with these are crucial in terms of the various forces involved in physiology. blackwell: turning to the first one in handcuffs the very first one, what is the effect ofpp the handcuffs in the context of what happened to mr. floyd? >> the handcuffs are extremely important with mr. floyd. the handcuffs on their own just handcuffs per se are not that important it has to be combined with the street. b because of the positioning of the handcuffs on the back and how they were not on - - manipulated by both officer chauvin and t4 they manipulated the handcuffs pushing them into his back and pushing them high.

then on the other side, you have the street. the street playshi a crucial part because he is against the hard asphalt street. the way they push down on his handcuffs combined with the street, his left side particularly the left side , the left side is in a vice. it is totally pushed in and squeezed from each side from the street, at the bottom. and then from the way the handcuffs are manipulated. it's not just the handcuffs, but how they are being held and pushed and where they are being pushed that totally interfere with central features of how we breathe. blackwell: so he is pancake between the pavement and they have force on top of him. >> precisely. blackwell: how this mechanism the handcuffs and the street explain the shallow breathing

that you describe? >> this gets back to how we breathe. this is fairly simple. the way w we breathe, we have two big muscles. we have the diaphragm and the rib cage muscles. the diaphragm does about 70 percent of what we need for breathing and about 30 percent comes from the rib cage. when the diaphragm contracts for the rib cage contracts they expand the chest when you expand the chest air flows in from outside that's all that happens on respiration but to expand the chest there are two crucial actions that have to happen we refer to these by the terms bucket handle so if

you have a regular bucket you carry water and lift up the handle in the bucket the handle comes up like this. man you contractor diaphragm you are performing the bucket handle movement on the rib cage see you contract your diaphragm and each time you can see it yourself you can see the rib cage that is the bucket handle. the second movement you have is the pump handle. this reflects to the old water pump that would be in the yard pumping out water. the handle is at the top of the pump. you lift up the handle each type on - - time in the water comes out. that action you are lifting. this refers to the front and back movementf of the chest

wall. with the pump handle your chest goes out with each breath. you can do it yourself. as you take a deep breath from front to back you are expanding your chest the front to back expansion of your chest is with the pump handle. at the same time you do both at the same time. the chest is expanding from side to side and that is the bucket handle. both of these are occurring >> one moment.

i need to offer, your honor. we offer exhibit 951. >> any objection? >> i have an objection to this. sidebar? >> all right. sidebar. [inaudible conversations] [inaudible conversations]

but that means you can't breathe if you don't have the bucket handle in the pump handle working nothing is happening no air will get in there. blackwell: you have a photograph that you brought to better understand the pump handle and bucket handle? >> states exhibit 951. blackwell: do you recognize what this photograph depicts? >> is it an accurate portrayal of a certain incident? >> yes observe,

dr. tobin? >> what i observed is particularly in terms of the hands of the police a >> sustained. blackwell: in this case could you observe if mr. floyd's breathing was impacted by the street? >> yes. >> in terms of the hands of the police and the handcuffs particularly on the left side. they were forcing the left wrist up into his chest forcing it tight. highgh up back, it was absolutely no way that he could do any front to back movement.

then in addition, because of the knee that was rammed in against the left side of his chest can sometimes the knee was down on the arm and against the chest, so this would have the same effect. so basically on the left side of keep in mind the opposite side he was being squashed between the two sides. this means he couldn't exert the pump handle because the street blocked the pump handle there's no way he could do any front to back movement the way they were pressing and there was no way. because of then a he rammed in against the left side of his chest sometimes it was down on the arm. this would have the same effect. basically he would be totally dependent what he could do on the right side. blackwell: have you's selected any footage from the body worn cameras that depicts this? >> yes. blackwell: states exhibit 944.

describe what it is. >> what you see here. blackwell: the jurors do not see this. >> what i am seeing is the left-hand is being grabbed by the police officers the handcuffed left-hand question to his chest. said hepa cannot expand. >> [inaudible] >> i apologize. i apologize. blackwell: no the jurors can see it. >> my apologies.

blackwell: it is okay. what is the significance? >> with the yellow arrow, no you can see the officer is holding mr. floyd's left-hand. he is holding it very firmly. there is a firm grasp and mr. floyd's left-hand is pushed in against his chest. we can see on the side officer chauvin knee comes in compressing and against his side asis well. the ability to expand the left side is enormously impaired. also the size of the chain the right and left side is very short. the whole left arm is also pulled over it's preventing him also from expanding the right side.

i was focusing on the bucket handle and the pump handle on the left but you can also see here the repair feasibility to expand his chest and of course the key factor what you can see here the street has a huge effect because he is jam down against the street it is playing a major role in preventing him from expanding his chest. blackwell: clear the screen, your honor. blackwell: states exhibit 942. >>de identify it.

blackwell: you recognize this? >> yes i do. blackwell: states exhibit 942. >> received. tell us doctor tobin what is the significance of what we see here? >> is slightly different of the two images married together. if you look on the left side his finger is pushing against the street. you also see the hand of the officers around his left hand you canou see the left

handcuffed arm here is a more clear view how it is rammed into the back of his back there is no way he can expand that. that the left image with the finger on the street been on the right you can see his knuckle against the tire. to most people this doesn't look terribly significant but to have physiologist it is extraordinarily significant. because this tells you he has used of his resources no is literally trying to breathe with his fingers and knuckles. when you begin to breathe you start with your rib cage and diaphragm after that is the sterna muscle the big muscle in your neck when those are

wasted up, then you rely on these types of muscles like your fingers to stabilize your whole right side he is totally dependent to get air into the right side. he is using his fingers and his knuckles against the street to crank up the right side of his chest. this is his only way to get here on - - air into the right lung. blackwell: states exhibit 938. r is this a related series of photographs and images? >> yes. >> no objection. blackwell: tell us what we see here. >> the top handle is the same as the bottom one that is just

the blowup from the top. the focus on the left-hand side is the shoulder. again, as i mentioned, when you have difficulty breathing you begin with the diaphragm and the red one - - the rid cage. one of the very last muscles he would uses your shoulder ouyou don't really use your shoulder for breathing. but on the left-hand side it is extremely prominent this is what people in the gym would call sculpting of the shoulder muscles they stand out very prominently. at this point on the left-hand side he is taking a breath using his shoulder and on the right side between the breath he is relaxing. he is breathing out. the two are shown you can see the market affect but realize

the shoulder is a very ineffective way of breathing because at that t stage the chest has alsot expanded when you contract your shoulder you get very little air it's a very poor way of breathing but it's what you have to do when everything else is failing. for extreme you use your shoulder to breathe. blackwell: doctor tobin, have we covered the first item handcuffs and the street? >> yes. blackwell: number two. knee on the neck. explain why neon the neck is so significant. >> it is extremely important because it will include the air getting in through the

passageway. blackwell: is a possible doctor to demonstrate with the anatomy lesson that may be relevant? >> to understand the knee on the neck, you need to examine your own act like i am doing no. first, put your index and thumb at the top of your neck you'll find your adam's apple you will find it. it is a very sturdy structure because it is surrounded by cartilage. it protects the voicebox, the larynx which is essential for speech. any amount of compression on the adam's apple will not compress it. it is a strong and sturdy structure.

then you go down from the adam's apple and there are little bumps below that the windpipe. or trachea because of the cartilage there and the knee on the front part of that will not cause compression. but then bring your finger to the top of your adam's apple no you directly over the type of status the crucial area and mr. floyd. this is where the hypopharynx is located on your service anatomy. blackwell: why is the hypopharynx important for understanding this case? >> it is very important for understanding this case for a number of reasons. it is vulnerable, no cartilage aroundt' it, an area that is

compressed, extremely small to breathe through as it becomes veryco important to continue to breathe through. blackwell: doctor, states exhibit 937 could you identify for the record what is depicted? >> 937 is the hypopharynx. blackwell. >> 935 is the hypopharynx with the coin. blackwell: do these two images fairly and accurately depict the hypopharynx. >> they do. blackwell: i offer states exhibit 935. 937. >> received.

blackwell: show them to the jury. doctor, using exhibits shown can you help us to better understand what the hypopharynx is and what it does. >> what you areou looking at here, where i have drawn in red is the top of your tongue above it is the empty space and above that. [inaudible] then the tongue comes down along here and the critical structure in this case because the active speech and mr. floyd becomes very important how he could speak. the structure that gives the speech are the vocal cords right here in the voicebox in the larynx. than a little area here called

the epiglottis it is a little sliver that prevents food going the wrong way when we are swallowing we use it both for swallowing and eating and the hypopharynx for breathing if we are breathing beer comes into your nose and mouth and down to the hypopharynx through the vocal cords and into the windpipe into the trachea and down into the lungs. if you are y swallowing the trapdoor the epiglottis will prevent the food going into the air passages and directed into the food tube at the back of the esophagus. the area of the hypopharynx is exactly from the base of the epiglottis, the first yellow arrow down to the second which is the larynx and just that little area that is the size of the hypopharynx.

>> we know that cross-section of area, i have a hearing millimeters. those are difficult to remember but right in the middle of this would be the size of a dime. basically the dime is the size of at the hypopharynx and tells you how small and aaffordable is this area if it will decrease in size it is a very tiny area. blackwell: why is the hypopharynx an important indication with mr. floyd? >> because they. hypopharynx is the area that will be vulnerable to occlusion from the knee on the. but in addition the hypopharynx has another aspect

that the hypopharynx is also controlled by the size of your lungs. as your lungs expand you increase the size of the hypopharynx with every breath there is a regulation of that going on. blackwell: was mr. chauvin applying pressure to hypopharynx that you observed? >> at different times. it varied from timepr to time. blackwell: are you able to tell us if mr. chauvin put his weight directly on mr. floyd's neck are you able to tell us what impact or effect that would've had on mr. floyd? if officer chauvin placed his knee directly on the hypopharynx, just the area of the diamond never varied and came in like a bull's-eye on a that area, then you would expect this area would become totally occluded.

but he varied the position of his head and officer chauvin also varied the position of his knee so it varied over time. blackwell: if it had become totally occluded than what? >> if it had been totally occluded, within seconds you will drop the level of oxygen to a level that oxygen deprivation the body resulting in a seizure or a heart attack. one or the other. blackwell: you have another photograph taken at the scene to help the jury. >> yes. blackwell: states exhibit 941. from exhibit 15.

do you recognize this photograph? >> yes i do. blackwell: states exhibit 941. >> received. blackwell: doctor tobin tell the ladies and gentlemen of the jury what you mean to convey with exhibit 941. >> look at the left but look at me first stick your finger in your ear and you draw a line going down through the vertical bodies of your spinal column you can get a line going down you're looking at that access that's what i have drawn here with the yellow dotted line. if you look here on the first slide you see mr. floyd's nose and face is directly facedown on the street it is not at any

angle. so feel yourself on your own neck and no if you put your hand at the back of your neck and you feel the bottom of your skull, here is the bone of the school and then you come down from that any but your whole palm of your hand . >> [sidebar]

>> the witness has asked you to do something on —-dash it was as if you were to do it you are not required to do anything we would not instruct

you to do but feel free to do it if you wish. blackwell: doctor tobin go back to where you are explaining the anatomy and the backend the base of the skull. >> as i put my hand here at the back of my neck, and feeling the tip of my school then bring down my hand i feel the extremely thick ligament it is called the nuchal ligament as a put the full palm of my hand on that ligament it is so strong. that ligament is what you are seeing the knee is placed over on the left hand slide so within the directly over the nuchal ligament that can cause no obstruction because it is such a dense ligament that is what you see with the yellow i'm sorry the yellow diagonal

, that the book of officer chauvin knee is above the yellow line. the second, separate you can see mr. floyd has his face rammed into the street. because he is using his face here to crack up his chest. he is using his forehead and his nose and his chin as a way to help him get air into the right side of his chest another way to crank up his chest. blackwell: how do you contrast that with the right? >> no you see the orientation mr. floyd has changed and the position of officer chauvin knee has changed. it has come down below the yellow diagonal in this position there will be far

greater compression of the hypopharynx in this region compared with what you see on the left. on the left there is no compression of the hypopharynx but ifof you watch the videos over time you can see there is a variation over time as to where exactly is the location of mr. floyd's head and where is the location of officer chauvin knee. blackwell: in the photograph on the right, then he is exerting greater force on the hypopharynx. >> correct. blackwell: is it possible to calculate the amount of force? >> yes itt is. we can calculate the amount of force based on the weight of officer chauvin. his body weight taking into account with the gear that he carries and also remove the

weight of his shinbone and his boot subtracting these and then you can calculate the weight. blackwell: can you calculate the changes or narrowing in the space people have to breathe through? >> yes. separately. blackwell: is this again through breathing through a small opening like a straw? >> if you breathe through a narrow passageway, it is like breathing through a drinking straw but it's s much worse. breathing through drinking straw is somewhat unpleasant but not that unpleasant and then it gets much worse than that. blackwell: is a space narrows is it more difficult to breathe through? back enormously more we know that through physics.

blackwell: could also be calculated. >> yes. blackwell: that calculation is a specific to george floyd? >> no. anybody we know physiologically when you have that level of narrowing it would happen too anybody. blackwell: explain to the jury what those calculations would show of the effect with the airway on breathing. >> i believe there is an exhibit that relates to that [inaudible].

blackwell: [sidebar] >> received. >> exhibit 940. tell us what is depicted. >> this is a physiology experiment. what is the effort to breathe along the why access on - -

access. so the very bottom is the lowest curve that is normal. no narrowing so we see is the flow varies shown in red would be the normal flow of a 40 sexual man. we can see what is done look at the normal one than 60 percent airway narrowing 's l.

tobin. >> this is the science behind it. this is just the equation in physics that tells you how that works. and the key thing is this is more narrow than a straw. there is no bigger increase in the effort it is hardly different in terms of normal. but if you a get 85 percent narrowing, no you see the effort ton breathe increases seven.five times compared to no narrowing. so you see a huge increase in the work required. it becomes far more difficult to breathe as the narrowing becomes more narrow. blackwell: this is then science and the equation how that works. for me as a physiologist and focus on the square sign on top it is below the level of the equation it is the denominator. i know with that he will bey fine for a period of time no everything will increase enormously with the

exponential increase. that is what we see on the experiment done

really nothing happens at 6094 but it 85 percent it takes off and beyond 85 percent it could be even more. so based on the formula here, you can tell as you narrow the effort to breathe will become extraordinary high end at some stage unsustainable. you just cannot do it. blackwell: in this case with mr. floyd the narrowing was the hypopharynx? >> yes. blackwell: did the knee on the neck cause the narrowing of the hypopharynx by. >> yes. blackwell: given the changes you observed of mr. chauvin knee on mr. floyd over time, where any of those changes significant from the standpoint of placing pressure on the hypopharynx? >> yes. extremely significant. blackwell:er exhibit 947 means y weight is being directed down at mr. george floyd's neck. >> what you are seeing in particular here is the toe of no longer touching

the ground. all bodyweight is directed down at mr. floyd'she neck. many calculations i excluded h his leg and shoe because some of itt is touching the ground. here you can see none of it we are taking half of his body weight plus half of the gear and all of that comes directly down on mr. floyd's neck. blackwell: exhibit 943 did you assist in preparing this exhibit? >> yes i did. blackwell: would help you explain your testimony? >> no objection.

blackwell: your honor, clear the screen. doctor tobin what is exhibit 943? >> half of theod bodyweight . >> is not always eat. >> the reason that we are saying that is because the total is off is coming down 91.5 pounds n directly on mr. floyd's neck. blackwell: is that all? >> we see that the toe is off the ground

having his face smashed directly to the pavement. >> when is faces into the pavement, at that time it like one of the ones that i should do, coming down in the new, there's a huge know bodyweight back on his knees everything is directed down on his knee his shin and his toe and his boot. >> were there times mr. chauvin left knee was on the back of mr. floyd's neck? >> correct. >> that is a separate set of forces it is the same force but compressing a different area it is compressing inside his chest. blackwell: what about the times mr. floyd had his face one - - face >> how would you compare mr. george floyd's oxygen level that mr. derek chauvin was on top of him that first five minutes. >> we know that the oxygen levels were enough to keep his brain alive and the reason we know that is because he continued to speak over that

time. we know that he made various vocal sounds for four minutes and 51 seconds from the time that the kne on the ground. blackwell: for the first five minutes three seconds. how would you characterize mr. floyd's oxygen levels while mr. chauvin was ont top of him? >> the oxygen levels was enough to keep his brain alive because he continued to speak. made vocal sounds four minutes 51 seconds from the time the knee is placed on the neck. you cannot speak without a brain being active. so he is making the attempt to speak. >> [sidebar]

blackwell: your honor this would be a good time to take a break. >> 20 minute midmorning break

>> you are still under oath and take off your mask please. blackwell: doctor, turning

your attention back to exhibit 943, focusing on the restraint the first five minutes and three seconds in f particular mr. chauvin applied his weight to mr. floyd's neck >> correct. blackwell: why was that time. after the first five minutes and three seconds less significant? >> at that point where he extended his leguf that we see happening. at the point we f see that happening is 2421. that is whenis he suffers brain injury. we can tell from the movement of his leg the level of oxygen in his brain has caused

seizure type activity there are medical terms but basically he kicked out his leg in extension form. he straightens out his leg we see that as clinicians and patients when theys suffer brain injury as a low level of oxygen. blackwell: we will talk about that more in a moment. is it significant if mr. chauvin moved his knee off of mr. floyd's neck after he was unconscious? >> no movement happens around different time but obviously it's everything up to the time that we see the brain injury that is occurring. or officer chauvin moved after that has no material impact on the case.

blackwell: would help the ladies and gentlemen of the jury understand thatin if mr. chauvin is applying pressure on the side of the neck as we see in exhibit 943. how does that translate into narrowing of the hypopharynx? >> it depends on the orientation of mr. chauvin body and the orientation of his leg. and in particular and the orientation of mr. floyd where exactly is the orientation of mr. floyd's head. if the nuchal ligament is under officer chauvin knee there would be compression of the hypopharynx. if it moves to the side and officer chauvin weight comes down on the side of mr. floyd's neck, then you get

huge compression. blackwell: 943 in the first five minutes was any overarching me on the side or on the back? >> for the first five minutes, the left knee is on the neck virtually all theig time by my calculation the right knee is on the back 57 percent of the time. the reason i cannot say 100 percent most of the other time i don't get a good view the cameras move around. i cannot see it. for that crucial period of time, five minutes, three seconds i can see officer chauvin knee on his back over 57 percent of the time. blackwell: the third mechanism

the prone position. how did that have an impact on the nearing of the hypopharynx. >> facing him in the prone position has several different effects. particularly it also causes narrowing of the hypopharynx among other things the prone position does. blackwell: is there a concept of physiology referred to as long by elms? what does that refer to? >> that is the way lung specialist measure the size of the lungs in different locations and quantify in different areas what level of the long there is with different segments of the lung behave in different ways. blackwell: you have an u illustration to help c us better understand the concept? >> yes i have.

blackwell: exhibit 929. >> i identify. it shows lung function. blackwell: is it an accurate illustration? >> yes it is. blackwell: if one - - exhibit 929. >> received. blackwell: start at the beginning. doctor tobin explain we see in

exhibit 929. >> the chest is gray then we see the long it is the pleural space. as you look at the breath going in and out it generates the title volume. that is shown as a waveform at the bottom. that is what happens in somebody with regular breathing. blackwell. blackwell. >> your you can see the pump handle action of the chest. with each breath you can see air going into the chest that produces the title breath.

on acceleration. >> is there a standard or normal size of breath? >> yes virtually all adults people it is about 400 cc is the size of the title volume. same for men and women and teenagers andnd grandparents. c blackwell: can lung volume be calculated? >> yes further additional for long volume. blackwell: did you do a calculation for mr. floyd's lung volume? >> i calculated those out precisely based age, sex and height. blackwell: exhibit 939. does this reflect your calculation? >> yes.

blackwell: it's 930. would this be helpful to explain your testimony? >> yes it would. this is the long volume and mr. floyd when he is sitting on the sidewalk. the key long volume we are focusing on is that ee lv and expiratory long volume and that is crucially important to understand what happened to mr. floyd i calculate out his eelv to be 3840 that is what is shown there by the horizontal line. on top of that is the size of

each breath and underneath the purple area is the residual volume when you blow all the air out of your lungs when you are finished flowing and cannot blow anymore out that is the air still left inside your chest is a residual volume that is to leaders 2300 that is included in the eelv. everything below the horizontal purple line. the eelv sitting upright is 3840. blackwell: to help us understand better eelv is that

commonly referred to as oxygen reserve? >> the main oxygen stores are in the body, contained within your eelv where you store your oxygen reserves. blackwell: for the ladies and gentlemen of the jury, it is true not all the air you breathe and is exhaled out. >> no. the eelv the volume in your lungs in between each breath. when you are breathing in and out between the next breath what is in your long is your eelv. blackwell: the residual volume is that also residual oxygen the body can use? >> yes the oxygen reserves you have are included in the eelv and obviously a subset is a residual volume. all below your title volume is oxygen reserves.

>> explain your calculations for mr. floyd's lungs. >> based on age and sex and height we see exactly eelv sitting upright is 3840. residual volume is 2300. blackwell: the amount of air he takes in title volume is the same as anyone else. >> 400 at the top the pink going up and down that is the same for anybody. blackwell: 400 cc cubic centimeters. >> correct. blackwell: the oxygen graph on the side what does that depict? >> the levelel of oxygen varies with age this is the level of

oxygen you expect in a 46 -year-old man. the level of oxygen measured in pressure if you did the arterial blood gas of somebody took out a sample of blood that's ath level of oxygen. eighty-nine the units we use our parts mercury when we describe levels of oxygen. blackwell: you told us mr. floyd being in the prone position served to narrow the hypopharynx or decrease the volume of oxygen in the lungs. >> multiple effects because the eelv is very important it is where we store the oxygen but ity. has an effect on the upper airway. when you breathe then, you don't notice it as you expand your lungs but at the same

time, the size of the hypopharynx also widens because of those forces that are occurring a part of normal breathing that you inhale and expand your lungs but also expand the area you have to go down that is influenced by the size of the eelv likewise then the size of the opening of the hypopharynx would alsoo be less it would collapse down as the eelv goes down. blackwell: did you actually calculate the reduction of lung volume for mr. floyd due to prone position? >> yes i did. blackwell: can a show exhibit 927. is exhibit 97 a calculation i am referring to? >> yes.

blackwell: i offer exhibit 97. >> received. blackwell: doctor tobin tell us we are seeing exhibit 927 relating to mr. floyd in the prone position. >> it is smaller when placed facedown. you are getting a decrease in the expiratory lung volume because in part if you live

flat in the bed with your face in the pillow, laying prone, facedown you can no longer use the bucket handle action so your lungs will get smaller you also have greater difficulty to use the bucket handle action. as you lay facedown your belly rises up into your chest so the diaphragm raises and the lungs get smaller so anybody turned prone you can see the lung volume on average goes down by about 24 percent by simply turning prone. with the smaller lung volume, less reserves and also affect the hypopharynx. blackwell: if it goes down to 24 percent do oxygen stores?

>> by 24 percent as well once you have less volume inside your lungs, your oxygen reserves will go down proportionately. blackwell: is it absolutely 24 percent? >> no. in physiology we look at the average change that happens with experiments >> so is the 24% reduction significant in the case o but in biology there is always a certain amount of biological variation. there will always be something like a variation he would see around these numbers. but when we speak of something we speak in terms of the average change that is occurring. blackwell: the 24 percent reduction because then we get

a proportional reduction in the size of that. in addition when you are turned prone the breathing goes up because the stiffness of your lungs changes in the stiffness of the chest wall changes so the person has to do more effort to breathe in that position. blackwell: the hypopharynx is linked to the size of the long? >> yes. blackwell: help us to understand. is it true some person suffering from covid are treated in the prone position? >> absolutely. it is a different scenario. in any patient with pneumonia in particular with covid that

any patient with pneumonia, when you turn them prone it can help that with pneumonia they have bad matching between the blood vessels going to the lungs. we saw the movie at the beginning you saw the alveoli all the blood vessels around the bunch of grapes. people who have pneumonia or covid, that matching is very bad that's what leads to the worst oxygenation in those patients. if you flip them prone, some

show no improvement but a substantial number the matching gets better between the blood vessels and the air sex. you cannot predict until you turn the patient prone you don't know which ones will do better but some of them do. this is why prone has been very valuable in patients with covid but a that is in people with pneumonia it does not apply to people with normal lungs. blackwell: also a lot of people sleep in the prone position. is a dangerous? >> no. for the average person you have so much reserves. a drop ofrm 24 percent for you will not have any impact

because you have a huge amount of reserve. but if you have somebody who drops the lung volume by 24 percent and then they have to cope with a neon the neck and has to cope with having the arms pushed up and unable to move the left lung and that is a whole different kettle of fish. blackwell: have we covered the third mechanism of the prone position? >> yes. blackwell: let's talk about the fourth one. which is the any onn the back, arm, side. >> m yes -- let me ask this. forget that question. does it matter whether the right knee was on mr. floyd back or left arm or his site. >> was no. it's really all about into the same. because we talking again back to the bucket handle and the pump handle. so whether it's on the back or rand in against the side and down on the arm, all of these are just going to markedly impair your ability to be able to move your chest with your bucket handle and your pump

handle. you just can't do it. it's all rammed in. also the whole time in this case you have to constantly keep in mind that this is taking place on the street. the street is playing a huge part because it's coming in in the front and totally preventing every action happening on the front. >> did that influence mr. floyd's oxygen reserves? >> yes, they are going down. once the eelv goes down every proportionate decrease you are seeing in the eelv you are seeing the same proportionate decrease in the oxygen stores. >> were you able to calculate what that influence was? >> yes. >> i want to share what is marked as exhibit 932. and ask you, dr. tobin, does this reflect the calculations that he did? >> yes, this does. but now you see -- >> one moment, doctor.

your honor, i want to, i offer exhibit 93232. >> any objection? >> no objection. >> 932 is received. >> now doctor please tell us what we see in 932. >> what you were seeing now is that networks no longer just prone. now you have the knee on the back in addition or the knee on the side. and so it is, this is going to her the compressed down the eelv. so here you are seeing that the eelv is now being really squashed down. so by the combination of turning him prone and also having the knee on the back you are seeing a 43% reduction in the eelv, which means that there's also a 43% reduction in his oxygen reserves, which means there is also a huge reduction in the

size of the hypopharynx. because this is directly linked to the hypopharynx, and you will see how this is linked. and so when you decrease the size of the eelv, that's going to cause it. and an additional effect is that your work of breathing goes up because when you are turned prone and with the knee on the back, now the work that mr. floyd has to perform becomes huge because he has to come with each breath he has to try and fight against the street. yester try to fight with the small volumes that he has and then he has to try and lift up the officers in the with each breath, and also remember yester try and also lift up the effect of the other officer pumping in his arm with a handcuffed arm. they are pushing it into his chest. so yesterday call these efforts to try and breathe against that.

>> so doctor when you tell us about a 43% reduction, 24% of that is just being in the prone position? >> correct. >> the of the 19% is the contribution of the knee on the neck? >> exactly. the other 19% -- so 24% from being prone and another 19% coming from the knee on the back. >> just so we're clear back. >> just so we're clear for the jury had his this translate into difficulty in breathing? >> again i did calculations of this, and basically you're looking at more than a threefold increase in the work of breathing, in terms of just from the effect of nothing else. that's even leaving out the effect of the knee on the neck. just some look at what's happening within the chest. so there's a huge increase in the work that mr. floyd was performing just to try and cope with what was happening below the neck, leaving aside what is happening above the neck.

>> doctor, i want to show you exhibit 922-926. and that you have a chance to see them i want you first to identify just what we are seeing in those before we show to the jury. >> yes, i identify. >> tell us please what it is for the record. >> we are looking at the effect of the lungs on the hypopharynx beginning with mr. floyd sitting on the sidewalk. >> your honor, offer exhibit 922 through 926. >> any objection? [inaudible] [inaudible conversations]

>> no objection. >> 920 through through nine it is my sixth inclusive are received. >> doctor, if you walk us through these help us understand a link of the hypopharynx in the case of mr. floyd. >> right. before you look at the hypopharynx just looked down at the lungs and you see that the lungs as you'd expect their expanding with each breath. you see the type am going to pick you can see the pump handle action, the lungs are getting bigger, the back then you see that exactly as the lungs are expanding, if you focus up in the yellow box and then the yellow box is enlarged over on the right side. and you can see that as you inspire, the size of the hypopharynx is also inspired come is enlarging. so you were seeing both of these happening, so it is the effect

of the of the lung volume, how it influences the opening of the hypopharynx. and this is sitting on the sidewalk. >> so looking at exhibit 922 what do we see here now in the prone position? >> so now we see mr. floyd after he is turned prone and now we can see the lungs are smaller than they were because they fall as we know when you turn prone. and then you also see now that the area, the hypopharynx, is further narrowed because the lungs as they get smaller they have less effect in keeping it t open. and so that gets smaller. >> okay. >> and then we have the knee on the back, and now we with the knee on the back, then the lungs become further reduced like i showed you for the precise calculations of the volumes and now you see here is the size of the hypopharynx further is

shrunk as result of it. so the opening through the hypopharynx is impacted by the knee on the back. >> and if we compare them altogether all three -- >> you were seeing than her altogether. on the left is sitting on the sidewalk, then just the effect of prone and then the effect of prone with the back compression. you can see the arrow is pointing out to you on the first one what is the hypopharynx right, that area, and with -- you can see it is expanding when he is sitting down. and then when he is prone and when he is prone with the back compression. you are seeing that the area of expansion is skating smaller, as exactly as what you would expect to happen.

>> going back to mr. floyd salon volumes, dr. tobin, is there a point in time when you determined -- mr. floyd's lung volumes -- where mr. floyd does not have enough oxygen in his stores remain conscious? >> yes, there is. >> and when was that? >> the time in terms of the loss of consciousness was 24:53. we can have precise in terms of where the absence of consciousness occurs. >> and can you tell bifacial features? >> i mean, this is something i do not as a physiologist but as an icu doctor. we are always looking at facial features to be able to tell how conscious somebody is. and we can tell how your eyes for how you move with the n your face, and that you will be able to tell is the person conscious or unconscious. it's a very important sign in

patience as we are taking care of them, to be able to monitor that and in the primary way we monitor it is by speculates i would've done this millions of times. >> do you know, dr. tobin, what is oxygen level would've been at the time he went unconscious? >> yes, we also know that at the time you get somebody who is in the situation who is at risk, we know that the moment at which you lose consciousness the level of oxygen in your blood will be 36 here at the number that is associated based on very hard scientific data telling us that. >> and against the normal level of oxygen was -- >> in mr. floyd was 89, and a 46-year-old man you man you expect the normal level of oxygen is 89. the level at which you would have an absence of consciousness then would be 36. >> doctor, i want to shoot

exhibit 928. -- show you. if we could clear the screen, your honor. first for the record before we show this to the jury can you just identify what is exhibit 928? >> we look at the effects on mr. floyd's oxygen as result of all the various maneuvers that are being done to him. >> your honor, i i offer exhit 928. >> any objection? >> none your honor. >> 928 is received. >> so tell us, dr. tobin, what we see here in exhibit nine under 28? >> we are looking at, i mean whitney kent the level of oxygen when i saw it, begin with a level of oxygen of 89, and then we see that it falls down to 36. the slide is looking a bit different than what i saw

before. so here you see that the level of oxygen forehand is 89 and then at the point when we notice the lack of consciousness in his face that the level of oxygen dropped down to 36. so that tells you, that tells you for the time of the loss of consciousness. and we know it continues from their, from the time that he stopped breathing, which is 20:25:16 and then i calculated out that from there on that you can calculate based on a given very rigorous science when the level of oxygen would have gone down to zero. but this first one we are looking at the level, the loss

of consciousness at 36, and that's happening at 20:24:53 and we are able to tell that by looking at his face. >> and 20:24:53 is 8:24 p.m. and 53 seconds? >> correct. >> was a point in time when mr. floyd no longer had any oxygen left in his body? >> there is because once again when he stops breathing at 20:25:16 then it would take another 25 seconds for the level of oxygen to go down to zero. at that point he would have enough oxygen left in his entire body. >> doctor doctor, i want tt exhibit 931. >> okay. >> and ask you first if you adjust tell us what it depicts before we show it to the jury.

>> yes, that is it showing exactly. >> what you receipt in 931? >> so what we are seeing in 9:30 one is that his level of oxygen has got all the way down to zero. >> so we will show this to the jury but first let me move to admit exhibit 931. >> any objection? >> none, your honor. >> 931 is received. >> dr. tobin would you explain what we see in exhibit 931? >> we are seeing the love of oxygen has gone down to zero, that there is at that point does not an ounce of oxygen left in his body. and again this is totally calm you can figure this out with very precise science looking at once somebody stops breathing what would be the level of decline oxygen how long it will take to reach zero. so we see here that he reaches a level of zero of oxygen at

20:25:41 ansell at that point does not an ounce of oxygen left in his body in his entire body at 20:25:41. >> so was the knees and lifted off his neck at the point there was no oxygen in his body? >> no. than need be made on the neck for another three minutes and two seconds after we reached the point where there's not an ounce of oxygen left in the body. >> thank you, doctor. are you aware of a study suggesting that putting someone in the prone position and putting a weight on the back is not dangerous pgh yes i am aware of these studies. they largely come out from san diego from the group of dr. chan and his colleagues. >> are you able to generally characterize the nature of the study for the jury? >> the bottom line is they are highly misleading.

>> are they relevant to the analysis you have just given to the jury this morning? >> no, they are not relevant to the analysis we have gone through this might. >> help us understand why. >> okay. the problem is in these particular studies, i mean i don't know how many and total but could be close to ten of them, and where they take people -- first of all that take perfectly healthy volunteers here if they bring them into the physiology lab and they lay thin flat input of matt on them which is different from the street and they put weight on top of them so the weights could be led weight in bags or in many of them they use kind of the barbells that you see in the gym like an olympic wheel that you see in the gym for weightlifting, and they place those on the back of the subjects and a measure various lung volumes it's a typically they will measure what we call

maximum ventilation. these are specific types of lung function tests that you don't need to bother with but they are showing a decrease in lung availability of around 35%. that's a substantial decrease in your lung volumes that you are finding. and then they conclude in virtually all of their studies that that level of decrease in lung volume doesn't matter because there's no change in the level of oxygen. and so, therefore, it's not clinically relevant. the problem is in doing a study like that oxygen is the exact wrong arctic to be using in a study like this. what they needed to do is continue to measure out the changes in lung volume like the eelv showing what happens to this. oxygen will only fall at the very end. it's an extremely insensitive measure your it's very important but it's very insensitive to

know that stuff is going back inside the body. that's going to be a very late event. and so for their concluding of this -- >> do have another question? [inaudible] >> so to help us better understand, dr. tobin, are these studies measuring the diminution or decrease in the oxygen reserve, the eelv? >> no, they are not. >> i want to show you what is marked as exhibit 948. and does exhibit 948-point to one of the studies that you were referring to? >> yes, it does. >> would it be helpful to use

this like to explain your testimony? >> yes, it would. >> your honor, we would offer exhibit 948. >> any objection? >> none, your honor. >> 948 is received. >> so look at the slide, dr. tobin, what does this tell us in terms of, for example, the surface area that is involved of the weight on the back. >> so if you look at the subjects back you can see here that there are four weights out of the gym that a place on the back of the subject. and the big wheel out at, and olympic plate come is going to have a diameter of 17.5 inches. see you can measure the cross-section of very of that is going to be 240 square inches. the trouble is that when officers kneel on the back of a suspect they don't place and olympic wheel on their back. they place their knee and so the

sectional area of the knee is 24 square inches, which is one-tenth of the area of the big bells you are looking at here. and so we know from simple physics that pressure is forced over area and so that is 240 divided by 24. that tells you that the pressure being exerted on the back is ten times more than what the san diego people are training. they are off by a factor can. >> so the pressure being exerted by an knee is ten times greater is what you're saying? >> ten times greater than come is going to be affected by the bell here that is shown out of the gym, the bar that you're looking. >> do any of these studies involve an knee on the neck? >> nobody has been any studies involving the knee on the neck. i suspect it would have major trouble getting that through the ethics committee in any medical school. >> do any of the studies go on for nine minutes and 29 seconds?

>> no. they are all very brief studies. >> said doctor come have we now covered the four mechanisms that resulted in mr. floyd schaller breathing and reduction of the hypopharynx? >> yes, we have. >> -- shallow. >> were you or are you aware that mr. floyd had some pre-existing health conditions? >> yes, i am. >> and how are you aware that? >> i read them in the records from hennepin county and obviously also saw been mentioned in the autopsy. >> do you have an opinion to a reasonable degree of medical certainty as to whether a person who had none of this pre-existing health conditions, a healthy person, would have died under the same circumstances as mr. floyd? >> yes. a healthy person subjected to what mr. floyd was subjected to would have died as a result of what he was subjected to. >> are you also aware that mr.

floyd was found to have type of tumor known as i picking glioma? >> yes, i yam. >> and for the ladies and gentlemen of the jury , what is a pair glioma? >> it is a type of a tumor that is found in the parable indians come sometimes in the pelvis. >> is the finding of this significant to you as relates to mr. floyd and his death? >> no. because one of the key things about it is it is called a 10% tumor which means 10% of people secrete adrenal but that could be important but 90% of them don't secrete adrenaline. so you don't -- nine out of ten of the time you have no increase in the amount of adrenaline. >> so if somebody were to die from a tumor, from some effect

would be a sudden death? >> yes. there's been six reported cases of people who have had those who died suddenly but that's the total in the literature, six. those people who died have headaches. mr. floyd complained of a lot of pain and a lot of different regions in the street but he did not complain of headaches. >> so in terms of reported cases where people have died from paragangliomas over the entire world there are six reported cases? >> yes. >> on all those sudden death? >> yes. >> did mr. floyd died of sudden death? >> no. >> i want to talk you about the different subject that the jurors may have heard one of the officers say if you can speak you can breathe. >> yes. >> is that a true statement? >> it's the true statement but it gives you an enormous false

sense of security. certainly at the moment that you are speaking you are breathing, but it doesn't tell you that you're going to be breathing five seconds later. >> so let's talk about kind of why this is significant. so could you tell us about something that may seem obvious, that is, what is required for speaking? >> right. for speaking you only speak when you're exhaling. you have to blow air out and then you vibrate the vocal cords and that's all there is to speech. so it is air going across the vocal cords, fenofibrate and you speak. but to speak there are two things important. one is you cannot blow air out if you didn't take a breath in before hand. so you must have had an inspiration in to speak. second thing is you cannot speak

if your brain is not alert. so when you see somebody speaking, you know that have had an inspiration momentarily before they are speaking, and that there is oxygen going to the brain at the time that they are speaking. >> and by inspiration you mean they haven't taken a breath in? >> right. >> was a time of mr. floyd's speech during the restraint import your analysis? >> yes, it was. >> why so? >> because it tells us for the time that he speaking and he continues to speak for four minutes 51 seconds from the time thing is placed on his neck, it tells us that there could not have been complete compression, not the been total inclusion of the neck at that time for that time because he's continuing to speak for four minutes 51

seconds. >> is a brain sensitive to oxygen deprivation? >> the brain do so sensitive to needing oxygen. >> what percentage is a body weight and how much oxygen doesn't does it consume? >> the brain is relatively small. it is only 2% of our bodyweight but it takes in 20% of all the oxygen that we take in. so the brain eats up oxygen at ten times the normal level. it needs a huge amount of oxygen because it's in the out millions of nerve signals every second. so it needs very high supply of oxygen. >> how long can the brain go without oxygen? >> that is well worked out. if you stop the flow of oxygen to the brain, you lose consciousness in eight seconds.

>> if you might recall mr. floyd's last words, i can't breathe, i those words significantly as a pulmonologist? >> yes. obviously they are important different ways. one is complaining to you of difficulty with reading but they are also telling me that at that time when he is saying please i can't breathe, we know at that point he has oxygen in his brain, but and again is the perfect example of how it gives you a huge false sense of security because very shortly after that we are going to see that he has a major loss of oxygen in the way that he moves his leg. and so it tells you how dangerous is a concept, if he can breathe or if he can speak he can breathe. yes, that is true on the surface but highly misleading.

very dangerous matchup to have out there. >> so if i'm hearing you correctly when he says i can't breathe that shows his brain is a? >> yes. >> i did meet them there wasn't? >> correct. >> and did you see or is anything in the video that you could show the jurors that they can see also that would point to the fact that his brain was a longer alert? >> yes. >> let me pull up exhibit 47 already in evidence. at 20:24. i'm going to play a a clip for you, dr. tobin, and then tell the jurors what they see afterwards.

>> so this key finding that you are seeing here, and that is when you see his leg going up come here to keep in mind he is prone so he is facing down. this is his leg coming up backwards. so that is what we call as clinicians, that is an extension of the of the leg and that is something we see when somebody suffers major brain, lack of oxygen. and it tells us at that point he is having what are sometimes called myotonic seizure, sometimes called hypoxic seizure. there are different terms that are used to really all about to say that you are seeing here fatal injury to the brain from a lack of oxygen. >> it sometimes also called anoxic seizure? >> it has all of the step of words. there's lot of different words that are used but they all come

down to the same thing, that it is that at that point the brain is responding to be drastically low level of oxygen at present. >> and does the fact when an anoxic seizure reflect damage to the brain? >> it indicates severe damage to the brain. >> and the reflex that we saw with the likes coming up, , is that an involuntary reaction? >> it is an involuntary reaction. there are a lot of different medical terms we apply but the bottom line is that you are seeing that the leg jumps out like that as a result of fatally low level of oxygen going to the brain. >> we talked about the brain injury. we also told us earlier about low levels of oxygen potentially causing pulseless electric

activity. >> yes. >> is a also then evidence of low oxygen? >> right. so, i mean, we have low level of oxygen that's going to show up in the brain and is also going to show up in the heart. and when it shows up in the heart it's going to cause the heart to beat abnormally. and the particular way that it happened in mr. floyd was you develop a particular arrhythmia called p.e.a., which is pulseless electrical activity where we are seeing their electricity in the heart but it is not resulting in any mechanical force. that is why it is asked that name. so it's the low level of oxygen is producing both. we don't see that dea and tell that is shown up on the ekg in the angeles. so it's much later that we see the evidence of it in terms of

display. but here we are seeing huge evidence in terms of the leg. the lake is crucial here because this is the time, the first time you are seeing there is major oxygen damage. >> so we reach the point where mr. floyd couldn't speak due to low oxygen. was it any correlation also to a narrowing of the airwaves that present his being able to speak? >> yes, as well. >> i want to show what is marked as exhibit 934, 936 and 933. and just tell us what are these images, in general? >> we are seeing again the same mri but as a different view of it that we looked at before. >> i offer exhibit 934, 936 and

933. >> any objection? >> no, your honor. >> exhibit 934, 936 and 933 our received. >> is a doctor, tell us what we see here starting with the first -- >> this is the same mri you saw before, but what you are being, your attention is drawn to by the yellow arrow is the vocal cords. and the vocal cords is simply how you speak. so to speak you must inhale. you must take care into your lungs and then when you let the air out of your going to vibrate those little vocal cords and that's what makes the sound of speech. so here we see the size of the windpipe, the trachea, and this becomes important in terms of speech.

because our knowledge about the influence of the size of the trachea, the windpipe for speech, is from patients who have had an intubation to in place and it is to develop scarring after that pixel as a result of the scarring we know what is the point of how much scarring in your windpipe will prevent you from speaking. answer these are just the dimensions. so as you know what is the size of the normal trachea. it is between a quarter and a time, as you can see here in terms of the diameters. >> next slide. >> and here is when those coins have been shrunk to 15%. and even when the trachea has narrowed all the way down to 15% you are still able to speak. even when the whole 30 windpipe is just the size as i shown here i have shrunk the size of the

coins you are still able to speak. so it tells you how dangerous it is to think, well, if you can speak, he's doing okay. because at this point you will be able to speak, but again if there is a small increase in the amount of narrowing here, not only will you not be able to speak, you won't be able to breathe. you won't be able to live. so it is a very dangerous thing to think that because you able to speak you are doing okay. >> and so, doctor, you're not able to speak, briefed or live once the airway narrows to below 50%? >> correct. you go from 15% you will still be able to speak and then as it gets lower from that, initially you'll be struggling and then at some stage you just won't be able to do anything. >> if we could show exhibit 940.

it's already admitted. >> so again this is exactly -- this is the same experiment i showed you before. and it just so happens this is pure coincidence. it's at 85%. you look at the top curve and that's the same number that we showed you on the mri. this is pure coincidence but you can see here once you're up at 85% that the work of breathing is enormous at seven and a half fold increase. and then as as a narrowing wd get further and further, then the work will become unbearable. so again it just emphasizes at the point where you can't speak and you are in deep trouble. >> on doctor, i would like to transition now from talking about the physiology of breathing to talk about your work as a clinician, taking care

of patients with respiratory troubles. does that experience factor to your opinions they also? >> yes. >> did you do anything to try to understand mr. floyd's actual rate of breathing? >> yes, i did. >> why was at important to do? >> because a major part of my work as a lung specialist is looking at people's breathing. you get an awful lot of information by looking at how the breeze, by looking at how they use her chest wall. all of this is extremely informative. and at the lowest level, one of the simplest things to do that is a station informative is simply to count how many breaths somebody takes in. it's one of the five sites like blood pulse, temperature, , it's one of the signs that tells and gives us a lot of clues as to what is happening inside the body. >> is a something you have done before? >> i have done it millions of

times. >> do you train others in -- >> therapist, medical students, doctors in how to do it. >> and so you are counting the breaths. do you observe the muscles and things also? >> separately from counting the breaths you're going to look at the different muscles there you think of whether using their student mastoid, what type of bucket handle, what type of pump handle action, looking at all this, with some as old as me i can see all of this very rapidly. >> so did you take this clinical experience and apply it to your observations of mr. floyd's breathing in this case on the videos? >> yes, i did. >> was their video evidence from which you could take measurements? >> yes, there is. >> i want to show exhibit 43 that's already in evidence.

i want to play this, doctor, and afterwards tell us what we are seeing. in one moment it will start. >> so if you focus down here where the handcuff, where his arm is close to his black shirt is best placed place to u can count out his respiratory rate. you are seeing that is making respiratory rate here. then another. and so we need to play it back so i need to tell you first where to focus. if you focus down there you will be able to count out the rates. >> we will play it once more so that you can count the rates to see what you are referring to.

>> one, two, three, four, five, six, seven, eight. >> so that was roughly a 17-second clip? >> right. >> and you can to seven or eight? >> between seven and eight. >> did you use this to calculate a rate of respiration? >> yes, because i mean it's simple once you have 19 seconds and you count out the number of breaths you have here and if it, said you count out to seven, that will come out at a respiratory rate of 22. >> is that number the respiratory rate of 22 significant to this case? >> extremely significant. >> why is that? >> because one of the things in this case is the question of fit

no. and if fentanyl is having an effect and is causing depression of sedges, the stench of that control breathing, that's going to result in a decrease in the respiratory rate and it is shown that with fentanyl you expect a 40% reduction in the respiratory rate. so with fentanyl his respiratory rate should be down at around ten instead of that it is right in the middle at normal at 22. >> so you didn't see a depressed rate of respiration or breathing rate in mr. floyd's? >> no. it's normal. >> and so what does that tell you bottom line with respect to -- >> exactly come in terms of fentanyl, the major, one of the major changes you see in fentanyl is a slowing of the respiratory rate. and again we would be expecting a 40% reduction in the

respiratory rate with fentanyl. the normal respiratory rate is 17 breaths per minute, plus or -5. so that that would be a normal respiratory rate of between 12 and 22. that's the the normal range of respiratory rate. and so it was with fentanyl you would be expecting a respiratory rate of ten instead, you can't get yourself and you can see when you counted yourself the respiratory rate is 22. so basically tells you that there isn't fentanyl on board. that is affecting his respiratory rate senses, not having effect on his respiratory sensors. >> so mr. floyd's respiratory rate was normal at 22 just before he lost consciousness? >> correct. >> so the jury may have heard some other information in the case about the fentanyl related

to an elevated carbon dioxide level in mr. floyd's body in the emergency room. was that significant to? >> yes, that is very significant as well. >> also? >> because he is reported to have -- i take it back. he's reported to have a carbon dioxide level in the arterial blood in the emergency room of 89 that's a very high level of carbon dioxide, and so you have to take into account what are the factors that might have led to that. and there's particularly important factors in mr. floyd to explain why his carbon dioxide was found at 89 in the emergency room. >> would you first tell us what would normal have been for carbon dioxide level? >> the normal carbon dioxide level in you army is 35- 35-45 millimeters of mercury. that's the normal. you don't need the millimeters of mercury stuff, but they are

the units that are given in the hospital chart. >> so you said there were significant factors in case of mr. floyd. would you help the jury understand what those were? >> yes. the important factors are that we know that he made his own last spontaneous effort to breathe at 20:25:16. after that you can look at the videos and you see he makes no effort. he makes no breath the last breath he took was at 20:25:16. then we know after that he stayed on the street for another three minutes or so, then he is placed into the ambulance cot and we know that in the ambulance they attempted to put in an airway, and i jill, and you can see that on officer lane's bodycare. you can see all of that happening. and then you can see the time at which it actually successfully

insert the airway and when they gave him the first breath. and that is a gap of nine minutes and 50 seconds from when he last took a breath. >> why is that significant? >> that very significant because we can calculate what is the rate of increase in the carbon dioxide in somebody who doesn't believe. if somebody doesn't take a breath, carbon dioxide increases at a predictable rate. and that rate is up to 4.9 millimeters of mercury per minute. that it increases. and so he is not taken a breath for nine minutes and 50 seconds, so you would expect just on that basis that his carbon dioxide level would go up by 49. so you add 49 to the normal values of 35-45, and then you

add that and you get a value of between 89-and above so it comes out virtually identical to the value that they found in the emergency room of 89. >> so doctor, what is a punchline with respect to that? what does it tell us? >> the significance of all that is it's the second reason why you know fentanyl is not causing the depression of his respiration. what you are seeing is that the increase in his carbon dioxide that is found in the emergency room is solely explained by what you expect to happen in somebody who doesn't have any ventilation given to them for nine minutes and 50 seconds. it is completely explained by the. >> so when a person is not breathing then carbon dioxide which naturally continue to

build up in the body? >> yes. >> that's what matches what was seen in the o.r. for mr. floyd? >> precisely. >> you said there were other things that were significant that were related to the rate of respiration that we talked about, fentanyl. >> right. >> was or anything else? >> yes. the other things, there are two other things that are very important because you saw with your own eyes exactly his respiratory rate. and the first thing is that these you have somebody who is underlying heart disease and heart disease is so severe that it is been set that it is causing shortness of breath, that it is causing you difficulty with reading, if somebody has heart disease that is causing shortness of breath, virtually all of those patients are going to have very high respiratory rates.

.. the physiological response, where we are narrowing is a normal respiratory rate and that is what he has. the respiratory rate you see is normal, it's the expected physiological response in somebody who has their airway

narrowed. >> so doctor, we covered the mechanisms of how low oxygen occurs . as a clinician did you observe low oxygen in the videoshowing the last minutes of george floyd's life ? >> yes. >> what did you observe? >> in terms of what we are seeing is the changes in his facial appearance . thisbecomes crucially important .you see the effects of the low oxygen. >> have you seen thiseffect in other patients as a clinician ? >> yes, because i work in an icu where 40 percent of our patients die i am extremely familiar with seeing people dieunfortunately. when you see these changes,

you see the changes in the face . is the key way of noticing something happening is by looking at the effects on the face. >> doctor, i want to showyou exhibit 15 already admitted into evidence . 4:04. i want to play a clip and have you tell us what itshows . >> at the beginning you can seehe is conscious . you can see slight from pickering. and then it disappears. so one second he's alive and one second he is nolonger . >> could we just one more play it back so jurors can see it. just one second.

it is 20:24:53. and the speed is slow down after just so we can see. >> you can see he's conscious and then you see that he hasn't. that's the moment the light goes out of his body . >> i want to also show you a from another body worn camera exhibit , 43 .

from mister nelson. 20:22. and i want to play this for you also doctor and you can tell the ladies and gentlemen of the jury what this is. >> now he's blocking his right side. you can see how he's using his hips to try to rock the right sideof his body to get air . you can see him again pushing down to getair in . these movements of his head you may miss but he's having to use all his entire body to just try to get airinto that right side of the body . keep in mind the left side is nonfunctional from the way

they have manipulated him and pushed him into the street so he's constantly cracking up the right side of his body, you can see it right there to get some air into his right side of his chest. he's making repeated struggling movements. he's moving again the hips because he's using his spine to try and get them, those muscles to move air into the right side. and he's again trying to use his right arm and he's not able because of the chain, the small chain linking it over to the left side. he's pushing down that right arm into the street he's unable and he's unable to do it because of the chain and handcuffs. >> and at some pointmister floyd stops speaking and what does that tell us about his oxygen supply ? >> where he is not speaking it tells us the airway narrowing into his upper airway is more than any five percent. and then it's separate in

terms of the oxygen level. that we're seeing my face but they're all happening together. one is seeing how much narrowing there is in the airway but they're all coming in together. >> and then did the restraint stop at the time of the brain injury that he a arrhythmia. >> yes. >> the constraints stopped at that time? >> know, restraint continues after he seizes the respiratory efforts. when he's taking his last breath the knee remains for another six minutes 27 seconds after he takes his last breath. the knee remains. after there is no pulse, the knee remains on the neck for another two minutes and 44 seconds after the officers found themselves there's no burst. then he remains on the another two minutes 44

seconds. >> thank you doctor tobin,no further questions . [silence] we're going to take a lunch break until 1:30. under-

>> just a reminder, you are still under oath. >> yes. [background noises]

>> good afternoon. >> good afternoon. >> thank you for being here with us today. i'll take the chairs -- all right. i just want to review a few things with you, i don't think we will take too long but you are ultimately approached by the state of minnesota to the review of medical issues in this case, correct? >> correct. >> you volunteered to do this work at no cost? >> correct. >> you're not normally involved in criminal cases like this? >> correct. >> this is the first time you've ever been involved in a criminal case? >> correct. >> it was that reason he decided not to charge a fee. >> correct. >> when you are in other cases, what feet do you normally

charge. >> my charge in our. >> what your hourly rate? do not 500 an hour. >> you agreed to waive your hourly wait for this? >> yes. >> he felt it was an important case. >> correct. >> in preparation for testimony today, he met with the state numerous times? correct. >> you have opportunity to review all medical information obtained in this case? >> yes. >> that would include mr. floyd previous medical history? >> correct. >> autopsy and attending toxicology reports prepared in this case? >> yes. >> as well as investigative materials, police reports and things of that nature? >> correct. >> correct me if i am wrong but you are not a sexologist? your specialty is in pulmonology, critical care and

things of that nature? >> correct. >> you have an interest, an impressive resume relative to applied physiology? >> correct. >> you been honored extensively for your work in that regard? >> correct. >> you're not a minneapolis police officer? >> correct. >> there to take the training provided by minneapolis police department in terms of medical care comes nowhere close to your level of expertise? >> correct. >> you understand minneapolis police officers are not even emts? >> correct. >> a basic lifesaving certificate dealing with gunshots, chest seals, tourniquet and cpr? >> yes. >> so have had the opportunity to review body camera footage, correct? >> yes. >> i think you testified you watched these videos hundreds of

times? >> correct. >> you watched them from all different angles? >> correct. >> you have the luxury pulling things down, going into slow motion, still framing various times? >> correct. >> so your analysis of this case comes after hundreds, if not thousands of hours of time spent looking at this. >> i don't know the total amount of time but potentially. >> so then ultimately based on the review of all of that, you repair report and provided that to the state of minnesota late january this year? >> january 27. >> after that, you had numerous meetings with the prosecution team? >> by xoom, yes. >> including january 30 this year? >> i don't know the date but that sounds correct. >> if i were to tell you the dates dates were january 30,

march 3, march 9, march 17th, march 24, april 1 and 7, he wouldn't have reason to dispute me? >> i have no reason to dispute you we will you understand the meetings are provided to the defense? >> i do understand then spending substantial amount of time preparing the exhibits the jury was able to see today? >> correct. >> those were prepared by you or someone within your team? >> by me. >> you provided those to the prosecution in advance of today's testimony? >> correct. >> and you understand those were provided last night? >> i have no idea when but yes. >> so you have had a lot of time to prepare both yourself as well as the prosecution team in connection with the case, there to say? >> correct. >> you talked quite a bit about physics in your direct testimony, agreed?

>> yes. >> you would agree that physics or the application of physical force is a constantly changing set of circumstances? >> i would agree with that. >> you would agree with me when you look at the concepts of physics, these are constantly changing, right? >> all the time. >> constantly, no second -- milliseconds and nano seconds so if i put this much weight for this much weight, all the formulas and variations will change second to second, millisecond to millisecond, nanosecond to nanosecond? >> i agree. >> similarly, biology the same way? >> yes. >> my heart beats, my lungs breathe, my brain sends millions of signals to my body at all times? >> correct.

>> even faster than the speed of light? >> correct. >> millions of signals every nanosecond? >> yes. >> in your report you even discuss when you're talking about these instances, the physics or biology, what you're really talking about is a single nano second, all of these processes work at all times. >> correct, the way we calculate -- into one instant. >> right, you've taken this and boiled it down to a nano second. >> i wouldn't say that, it's obviously in my report, sequentially a chronology from the time the need is placed on the neck and then until your.

>> your report talks about the sequential nature but when we talk about the biology and physics of this, these are working simultaneously, contemporaneously altogether? >> correct. >> an incredibly rapid fashion? >> yes. >> you would agree with me that as this was occurring, there was nobody measuring units of force placed on any particular position of any particular person at any particular moment? >> nobody was there measuring at the time, i agree. >> that's when you calculate, what you have to do, boil it down to what you would call the average?

>> correct. >> so whenever we look at the concept of an average, there are things happening moments before, moments after, right? >> yes. >> forces will increase or decrease relative to the nano second of time? >> correct. >> ultimately when we talk about the biology of things, pathologists try to look at all intersections of all the things that occurred in a particular death investigation? >> they are not looking at anything to do physiology. >> understood but they are also looking at how other factors may contribute to the individual? they are basically looking -- >> it's a yes or no. >> yes partly. >> i'm looking beyond the nano

factor, agreed? >> in terms of a pathologist, they are looking at the nano second. >> but they are taking into consideration things simply that extend beyond physiology? >> they are looking primarily at psychology. >> so what causes the heart to stop, what causes the lungs to cease to function. >> they make an inference based on toxicological time. >> right. considering the multitude of biological factors involved in the death of a person, right? the same as any physician looking at that. >> in terms of your review, you

would agree the amount of time you spent looking at videos analyzing the videos from different perspectives and angles, it's far greater than the length of this? >> yes. >> probably to the times of thousands? >> i really don't know but substantially longer. >> right. ultimately, you conclude mr. floyd died for what we would call hypoxic death? >> low level of oxygen. >> low level of oxygen that caused damage to the brain which resulted in pulseless electrical activity, correct? >> not quite. >> how you frame it? >> low level of oxygen causing damage to the brain, the brain didn't cause it, low level of oxygen caused the damage to the

brain, low level of oxygen caused. >> an example of how multiple processes are occurring simultaneously. >> is just one process, low level of oxygen. >> is having an effect on multiple -- the heart and the brain and the lungs. >> it's just too, the brain and the heart. >> the brain and the heart. i think you call it -- is it the nuchal ligament. >> yes. >> that's the space at the back of the neck is very hard? >> long but roughly the size of your hand, stick the hand on the back of your neck. >> right you said it's a very hard surface? >> yes. >> they can withstand a great amount of pressure? >> yes.

>> so when we talk about the placement of the knee, there were periods of time where mr. chauvin to me was placed on that ligament based on your observation? >> yes. [inaudible] >> you had opportunity to review the autopsy? >> i did. >> you understand that there was no bruising either on the skin or under the skin surface noted by doctor? >> i am aware. >> you also are aware, he talked about the high both their next? >> yes. >> you are aware no injury was noted? >> i am aware. >> i found it interesting in your testimony and report talking about this notion of you can't speak or if you can speak

-- if you can speak, you can read, right? describe this as a very dangerous proposition? describe this as causing a false sense of security to people, right? remark yes. >> in your report you write a paragraph how physicians often times have trouble with this, right? >> yes. >> so people similar to yourself have been too medical school? >> yes. >> so intelligent men and women who have graduated from college and gone on to medical school are engaged in the practice of medical school sometimes have problems with this? >> yes. >> a patient comes in and says

they are having trouble breathing and often times a physician will not believe them, essentially. >> it's important to make sure we are talking about speech or difficulty in breathing because they are different. >> right, you write in your report that some doctors incorrectly consider patients to be hysterical. >> it's not proper -- overruled. [inaudible] >> you wrote some doctors incorrectly consider patients hysterical and imagine in nature which further aggregates patient distress. >> as i recall. >> you wrote you represent positions that you to understand the mental because of clinical. >> that's a different thing that, that type of syndrome is very different than difficulty in speech, they are apples and oranges.

>> but if a position, somebody is coming in and they articulate to their position, i can't breeze and hyperventilation syndrome and physicians often times, as you indicate confuse this issue? >> correct. >> they blame the patient. >> they don't blame the patient but they misdiagnose. >> when we are talking about speaking in breathing simultaneously, different considerations is a minneapolis police lieutenant who trains police happens to have testified that's a common statement in the course of treatment or training of minneapolis police, you might take exception with that

statement? >> i don't follow your question, it's very hard to hear. >> and i'm losing my voice, excuse me. if a minneapolis police officer, trying to talk closer to the mike. lieutenant who trains minneapolis police officers testified that frequently said, a person can talk, it means they can breathe, he would have a problem with that? >> they are able to breathe at that moment but a second later, they may be dead. >> and because dealing with any person a rapidly evolving situation back and change from second to second? >> yes. >> in terms of the calculations you've made, you would agree

calculations are generally theoretical? >> they are based on direct measurements, extensive research. >> but you're making certain assumptions, are you not? >> very few assumptions. >> you assume the weight of mr. chauvin dimock i am aware so obviously i am aware there are two different weights given. >> and you assume the weight of the equipment. >> yes. >> and you have not actually physically measured the weight of the equipment of a police officer carrying? >> no, i took the measurements that are important. >> and you are not actually weighing what mr. chauvin wade may 25, 2020? >> no. >> in your measurements, you appear to be, at least from my understanding, which is limited, from my understanding, your

measurements assumed equal weight distribution between right and left. >> yes, that's correct. >> so again, as we know as things change and evolve, weight is frequently redistributed? >> correct. >> in terms of eld -- am i saying it right? >> yes. >> you are facing those calculations on the presumption that a person is a healthy individual, right? >> it's not going to change really. >> but in terms of normal

respiratory rate, some other factors you put into your analysis, it's premise upon a healthy individual. >> it's based on a 46-year-old person of a particular height. >> whose healthy. >> correct. >> so you would agree if biology can change rapidly, the biological, specific biological conditions of mr. chauvin and/or mr. floyd come into play? >> correct. >> the volumes or figures you assessed in connection with this case, they are conditioned upon him being a healthy individual. >> it varies in terms of the lungs, say for example, compliance will vary but lung volume is pretty robust.

>> okay but other factors, like you said, was the first one? >> long compliance can vary from one person to another but different segments within the lung, they are not all monolithic. >> you've talked about one thing in terms of, this is a bit of a side, in terms of the prone position and pushing of the stomach into the lungs, the size of a person's stomach has some bearing on that? >> it does. >> a person like myself has a few extra inches, if i am prone, it's going to push further up into my lungs? >> correct. >> a person whose healthy, physical, muscular will have less of an impact? >> correct. >> but in terms of what we have learned about mr. floyd from his autopsy and medical records, we

understand this to floyd had some heart disease? >> correct. >> we believe in some of his arteries number between 75 and 90% of his ventricular arteries? >> correct. >> that will affect blood flow in a person? been a correct. >> it body will have to work harder to get the blood flow. >> not really. >> how does that affect a person's respiratory. >> the coronary artery to eat -- the coronary artery is affecting and if it was contributing to shortness of breath, you'd expect he be complaining of chest pain and demonstrating rapid rate, we don't see either. >> we'll come back restoration -- i can't say it right.

i'm taken by your accent. respiratory rate. >> compensator. [laughter] >> appreciate. >> 's territory great -- respiratory rate. we understand mr. floyd, based on medical records has history of high blood pressure. >> correct. >> in terms of, we also understand mr. floyd previously was diagnosed with covid. >> correct. >> he may not have been symptomatic march 25 but it's fair to say a lot is unknown about the effects of covid on a person's lung long-term. >> not as much as it would appear because obviously we have

a huge amount of information about long-term effects. >> and that can affect elasticity of the lungs? >> not elasticity, of its effect, it would be within the sensory receptors so it would not within this. >> okay but we learned about the toxicology -- excuse me, covid you testified that treatment of people with covid-19 includes leaving them in the prone position? >> right. >> those people who would be treated for covered prone position based on your calculations, you have a 24% decrease. >> this is people with covid during the time they have covid. >> so that is what you would expect, the same decrease. >> no, it's going to be different in somebody has say

pneumonia, what's going to happen in the prone position will vary from one person to another as a result of the pneumonia, different than normal. >> okay so in that sense, every person is different. >> for certain. >> you calculated his respiratory rate to be 22? >> correct the matthew said that was within normal respiratory rates? >> yes. >> you would not describe him as hyperventilating? >> the word hyperventilation is open for misinterpretation, that is certainly not hyperventilation. >> it assists in the removal of carbon dioxide from the body? >> it is not that simple. >> in simplest terms -- >> in simplest terms, it gets

rid of's carbon dioxide do not correct. >> frequently. >> in terms of the toxicology of mr. floyd, we did learn there were some controlled substances in his system? >> yes. >> we know there was, for example, nicotine, right? mr. floyd was a smoker? >> correct. >> smoking changes the lung function, agree? >> to some degree. >> we also learned -- i'm not suggesting all people who smoke have lung problems, right. >> 90% don't have any. >> go up to the microphone. >> i'm sorry. >> no problem. >> you focused your direct examination quite a bit in terms of fentanyl and it affects

respiration rates. >> yes. >> you would agree generally that fentanyl is respiratory depressant? >> they can be. >> it is used in operating rooms? >> yes. >> is also used in management of chronic pain? >> correct. >> medically speaking, those are the only two reasons fentanyl would be prescribed? >> yes, probably. >> but you understand fentanyl has become more prolific. >> yes. >> you would agree generally there is a significant difference between fentanyl manufactured according to the united states, whatever rules apply, right? the pharmaceutical companies making different than the street

dealers do? >> i would imagine so. >> so when a person is ingesting illicit street fentanyl, every time they take a fentanyl those, it is a different experience for the person? >> right but if it's affecting respiratory system, it will -- [inaudible] there's no way around it. they will not have an effect on respiratory. >> but the end result of fentanyl could include respiratory depression? >> right. ...

curfew conditions where the physician can lawfully subscribe that in phentermine right. >> yes. >> but it's an exceedingly rare that that's actually done pretty. >> we would be able to subscribe it commonly for other types of persons printed. >> and i think the 80 hud, is that right. >> yes. >> so. [inaudible]. we also know that adrenaline will increase the heart rate,

right. >> yes. >> and adrenaline can be put into the body in multiple ways, right. well, any things can cause a surge and adrenaline. >> yes. >> one of those things would be getting into a fight with someone. >> yes. >> for being afraid. >> and getting into a fight. >> and what was found and i understand that you call it the 10 percent tumor but in 10 percent of the tumor cases, that can cause an adrenaline surge. >> yes. [inaudible]. >> in terms of the use of fentanyl in the hospital setting, surgical setting, having become familiar with a what is called wooden chest center. >> yes. >> and can explain that pretty.

>> in some patients you get an increase in the chest - >> so the lungs become less elastic you pretty so that would prevent a chest wall type rigidity, also decrease the performance of the lungs pretty. >> it would impede the ability of the lungs to expand. >> in your report, you wrote you would expect the peak respiratory depression to occur prevent and five minutes of ingestion. >> right. >> i become to learn that tablets were found or controlled substances were found in the back seat of the squad 320 pretty.

>> i'm not sure with the status of the report is from that. >> so you've not been provided with any additional information since the time you prepared to report. >> i'm sure that is wrong, but i've been provided with a lot of thanks, i don't necessarily recall. >> will yesterday, we heard testimony from the state crime lab that they were in the backseat of the squad car. to punctually consumed bills, found in the back of squad pretty. >> objection. >> characterization of. [inaudible]. >> in his. >> you understand that pretty. >> no. i am not fully understanding.

>> yesterday, the chemist from the state crime lab despite in this case. >> ruling sustained in the form of a hypothetical predict. >> i am sorry your honor, cannot hear you. [inaudible]. [inaudible]. [inaudible].

>> let me ask you in the form of a hypothetical question. if partially ingested bills that were determined to contain both fentanyl and meth amphetamine were found partially ingested in the backseat of the squad car and that those pills have come with the dna of the deceased individual person, meaning they took them. in those pills would've been in his mouth at about 218. 42018. is it fair to say that you would expect the peak fentanyl respiratory depression to be taken in about five minutes pretty. >> i was a would depend on how

much of what was ingested. it won't tell you anything about whether it was ingested or some of it or anything. but, if there were any amount of it ingested, yes, the peak would be five minutes pretty. >> so if it happened at 2018 work there about when the individual was in the back of the car, you would expect that peak respiratory depression it to be around 2013, right pretty. >> you are really confusing me. >> i think i can actually say it is been a long week. so, 2018 is the injection point and you would expect peak respiratory depression by 2023. >> correct. brady. >> that beats continuing afterwards right. >> yes.

>> you've also described in your directed testimony, but you have interpreted to be in anoxic seizure right at 2024. >> correct., 202421. >> and that was what you saw in with the jury was reflected in from officer body camera from officer thomas lane. and it was the kick of the legs, right. and after that point you can see the officer thomas lane pull the leg down right and you can see it kick up again right. >> yes. >> sorry. >> i have a tendency to go fast. that is what you recognize and 46 years of being a

pulmonologist and intensivist in your experience pretty. >> obviously there was additional information but the leg was moving. >> and would be reasonable for police officer to interpret that same behavior as resistance. >> objection your honor argued. >> you testified that the last breath of mr. george floyd was at 2025, 16, right. >> correct. >> prior to the .12 people who were there would've appeared to have been breathing, right rated. >> is hard for me to say pretty. >> prior to that point. it would be reasonable that he would appear to be breathing, right. >> yes. >> in fact he showed us a segment where you could or you were able to count his respiratory rates right.

then you said at 2035 and zero six, sec. is when the first air was pumped back in. >> correct. >> and you understand that paramedics arrived at 2027 and 45 seconds. >> yes. >> so the time between the paramedics arrived and mr. five got his first air, was roughly eight minutes, almost nine minutes. >> yes. >> and according to the timelines in the drive to the hospital was about five minutes. >> i am sorry, i do not catch that pretty. >> were you aware that the drive to the hospital is about five minutes predict. >> i was not aware of it. i have no reason to dispute it.

>> between 2027 and 45 seconds, when emts first arrived, and the time they got him to have an error in his lungs, there was a result nine minutes. >> yes. >> your honor, i have nothing further. [inaudible]. >> doctor tobin, just a few questions for clarification sir. you had just been asked a lot of questions about science and medicine changing and constantly changing and evolving, by the nano second by the millisecond, you heard of this. >> yes. >> on the go to the time when mr. derek chauvin was on the

back of the neck of mr. george floyd, did you see him get off of the back of mr. george floyd by the nanosecond, by the millisecond, by any seconds for the nine minutes and 29 seconds that you thought. >> no i did not pretty. >> if you look at that time and three seconds and you focus on, or if you consider all of the nano seconds milliseconds, and five minutes and three seconds, where was mr. derek chauvin, the vast majority of that time. >> he was on mr. george floyd's neck and on his back. >> and that constantly changed pretty. >> no. >> now you ask questions about what injuries were noted pretty. >> yes. >> and i think the reference was made to the trend that hypopharynx pretty does it make any difference you whatsoever pretty. >> no less whatsoever. i would not expect that pretty because the effect on the

hypopharynx are not something that is going to remain at the time of an autopsy. the times changes that we see sing the somebody with sleep apnea, not tents something that you will see the following morning when you look at somebody. it is just not there. >> there is also a reference made from the absence of the neck and does that make any difference to you whatsoever. >> no because whenever i go to the chart i said in the heart of bentonite of the the bruising of my bottom when i leave. so would not expect anything in terms of that. so if you had somebody, it's not as if somebody is jabbing against it so you would not expect anything in the way the bruising to pretty. >> in the fact is there any correlation between the absence of bruising on an autopsy in the forces necessary to restrict breathing. >> no. the totally different because in terms of status forces and dynamic.

>> what about low oxygen. if nobody has suffered or dies from low oxygen. >> yes. >> does that show up an autopsy. >> no. >> in the fact that it doesn't doesn't have any meaning to you. >> it is not because low oxygen is a function just like arrhythmia is a function upcoming doesn't leave a fingerprint on the autopsy. it is just there, something that happened. but it won't leave any fingerprint afterwards, you don't see it. summa but it doesn't mean the person didn't die from low oxygen pretty. >> no absolutely not. and you can take so that he was suffocating with a pillow, this very clear to you after you've suffocated that the person is dead from the peloponnesian war not going to see the effects of low oxygen read. >> now you are asked quite a few questions about mr. george floyd's pre-existing health conditions and you cited a

number of those. and do any of those conditions have anything to do for the cause of mr. george floyd's death in your professional vignette. whatsoever pretty. >> none, whatsoever. >> on the cause of those conditions a manner pretty. >> the cause of death is a low level of oxygen. it was because the brain damage and the heart to stop. >> you are also asked questions about substance abuse and mr. floyd's it system. and i think that you were asked questions about nicotine, remember that pretty. >> yes. >> he didn't die from taking delete printed you are asked questions about fentanyl and meth pretty any evidence that he died from meth pretty. >> no, none pretty. >> u.s. questions about whether he had ingested any fentanyl within five minutes of his time of death pretty. >> yes. >> i think you explain to that us that if somebody is suffering from a fentanyl overdose, you would see a depression in the

respiratory system. >> yes. >> and depression been some repression in the rate of ability to breathe. >> correct. >> did you see any repression whatsoever in mr. george floyd. >> absolutely not. it was normal pretty. >> inhabitants than of any fentanyl and is system, depressed is bringing, it in any way whatsoever pretty. >> no. and further, carbonite and cut dioxide pretty. >> thank you doctor tobin, no further questions. >> two quick questions pretty in terms of the carbon dioxide level, you testified that it was at 896. >> ninety-seven predict. >> you testified that the carbon dioxide was at a 96. >> it was 89 pretty. >> and i was also measured at 102 pretty. >> they are teary is the one

that you need to look at. >> and in terms of the ingestion of that just generally speaking, fentanyl and also because - >> it would have to be due to respiratory depression pretty. >> fentanyl can also cause a death as a result of low oxygen pretty. [inaudible]. >> fair enough, thank you. [inaudible]. >> mr. nelson run a fentanyl could be at a cause of death factor pretty you're familiar with the way the people die from fentanyl. >> yes. >> today or do they not go into a, before the die from a fentanyl overdose. a. >> yes they would. >> and was george floyd ever in a coma. >> no. >> thank you doctor tobin. >> doctor thank you so much.

>> thank you. >> let's take a five minute break. [inaudible].

>> dr. tobin, is there . [inaudible]. [inaudible]. [inaudible]. >> do swear or affirm testimony that you're about .

[inaudible]. >> i do. [inaudible]. >> if you wouldn't mind removing your mask for testimony. and let's begin by having you speak your full name and spelling each of your names. >> my name is daniel eisen schmidt. >> thank you your honor. good afternoon sir. >> good afternoon pretty. >> what you are freighted. >> mss labs. >> in pennsylvania, how long have you been when this lab pretty. >> since 2011. >> when you do there pretty. >> i'm a toxicologist. >> did you have any other lab experience before joining them. >> yes, i did. prior to joining them from 1934

- 2011, i was chief toxicologist for wayne county, medical examiner's office and before that i was at medical labs and director of toxicology and prior to that, from 1982 - 1991, i was at maryland medical labs in baltimore, maryland and during the period also working sometime during i think it was 1986, as medical examiner's office in baltimore, as well. so adding this to your educational background could you describe to the jury. >> have a bachelors degree in biology from the university in new york and that was obtained in 1982. and i have a masters degree in pathology the concentration for in toxicology and that's the university of maryland, baltimore that was in 191986.

and though my phd was at the university of maryland, baltimore in toxicology in 1991. >> you have any specialized certifications. >> and board certified as a fellow at the american board of forensics pretty. >> and that the requirements are, they change of the years but for the fellow requirement, you can apply to board after three years after you had your phd. examine your conditionals to see that your active in the field of forensic toxicology and if you have the right references in your academia near field they will allow you to sit for the examination predict if you path the examination, the fourth of so on for your final certification and after that, you have to do continuing education each year. and obtain a minimum number of continuing education credits and then every five years, we have to have or reapply to the board

for accreditation pretty. >> have you measured hundred satisfied those credits successfully and are you up-to-date with all of the continuing education requirements as well. >> yes. >> i'm going to get back to your roll as a forensic toxicologist, can you describe your day today job duties as a forensic toxicologist at your lab you're currently at pretty. >> semi primarily responsibility is to do case review and what that means as when toxicology tests are performed at this lab, particularly ones that require different kind of test to be done. they wind up being reviewed by toxicologist or scientist to look at them in the context at all of that testing is done. individual tests are reviewed by the analyst in the laboratory and secretary ability as well but the final review come to toxicologist or scientist that looks at everything in the context of the entire case

pretty. >> in that capacity come as a part of your job duties to offer reports and sign off on all that testing pretty. >> yes. >> how any cases have you reviewed approximately. >> i review about seven - 8000 cases per year. >> in terms of the work comes in to this lab, are there a variety of agencies that present samples for testing pretty. >> yes from medical examiners and corners. and from police agencies, for dui cases and we also get a lot of clinical samples from hospitals and referral operatories. >> so in that capacity does mss receive postmortem or death related samples as well as limitations pretty. >> yes we do. >> and as a lab, approximate how any tests or samples are done each day pretty. >> about 12 - 1300.

>> when you say requisitions pretty. >> i would mean the testing or multiple samples. >> thousands of tests that year pretty. >> yes thousands of tests a day. >> so tens of thousands of test a year. all right, is mss, a license and accredited lab pretty. >> it is. >> and also national accreditations as well pretty. >> national and state accreditations. >> in this particular case, did mss labs received some samples for testing from a the medical examiner's office elated to george floyd rated. >> we did. >> and were there a number of different samples that were received. >> graham v. connor. >> what were the samples ultimately tested by mss labs.

>> we tested the samples that were requested by medical camp teeth examiner to be tested so we attested examples that were lame labeled as possible blood and also tested on urine that was collected at the autopsy. >> in terms of the testing that was performed at this lab, where those test pursuant to standard operating procedures at the lab. in the process was followed, all of those tests. >> yes. >> getting to the results from that testing, one for the notable findings from the testing pretty. >> most notable testings was the presence of fentanyl and 11 nanograms of - and the the breakdown product of fentanyl, and concentration of 5.6 nanograms per liter and in addition we found with an editing and 19 - >> each of the substances, 15180

you have indicated that these were the results from the hospital in this case is that right pretty. >> that is right pretty. >> so let's start with methamphetamine, what is it. >> so methamphetamine is a central nervous system stimulant. it can actually be described, it really is pretty can be described as under the name of oxen and used for attention deficit hyperactivity disorder and obesity and results in experimental use for the treatment of - and between 2016 and 2018, there was about 10000 subscriptions in the u.s. written for it each year. >> so can methamphetamine be both a street-level recreational drug also prescription drug printed. >> it can. >> with respect to the results of the 19 milligrams that you found of methamphetamine, what significance if any is there to that amount pretty. >> that is actually approximately the amount that

you would find the blood somebody that was given a single-dose of methamphetamine that was subscribed to them. >> so when you say they subscribe to the subscription drug form in which methamphetamine can be available, the results would be consistent with the subscription dose is that right. >> yes. >> would that be considered a low level of myth and that the main pretty. >> yes, very low pretty. >> and you also talked about the fentanyl results of the 11 anagrams per milliliter. first, what is fentanyl. >> so fentanyl is an opioid and - it is similar to morphine, but much more potent than morphine. it can be used to treat pain and also an adjunct use in surgery for anesthesia. >> and you talked about opioids, can you describe within hopefully i'd is pretty.

>> so, opioid actually include both natural, semi synthetic and synthetic drugs that act on receptor which they act. oh we hates our natural products that are found which is morphine encoding. so opiate or opioids have - >> what is an example of an opioid. >> so fentanyl is an example of opioid pretty. >> but oxycodone also be an opioid. >> yes it would. >> and you also talk about similarities between the two pretty and you mentioned morphine as an opioid. >> yes. >> is that heroin pretty. >> so heroin is actually made from more pain moment heroin breaks down, breakdown two metabolite and then it eventually goes to forming

pretty. >> so heroin breakdown into morphine and - morphine pretty do what toyota entered opioids have similar effects pretty. >> yes pretty. >> and getting back to fentanyl level in this case, you mentioned it it was 11 milligrams per liter, can the levels vary widely depending on and why would debbie pretty. >> because of tolerance. >> can you explain how an individual drug tolerance might affect the impact in particular drug like an opioid or fentanyl might have printed. >> so the person becomes tolerant to a drug, and they would have more and more of the drug to get the desired effect so, with chronic use the same feeling that you would in a concentration of fentanyl, you need to take more to get that effect pretty. >> so somebody is regularly using opioids or opioids, then individual within development

tolerant. >> yes. >> you also talked about another drug, can you describe what ideas predict. >> so so in the body gradually eliminates fentanyl, it breaks it down from fentanyl to more fentanyl and that's a gradual process that occurs over time. it is one of the ways that the body eliminates fentanyl. >> indicated that the mound of this and the hospital was the case of 5.6. is that right pretty. >> yes. >> what is significant about that amount of fentanyl. >> while it shows that some of the fentanyl was metabolized to more fentanyl and also could mean it was pre-existing more fentanyl with additional document on top of that. but basically showed that when we see very recent deaths with fentanyl, we frequently see fentanyl with no more fentanyl whatsoever because after a very acute intoxication, the body

does not have time to break it down. >> so can you describe and you see in overdose typical you may not see it. >> correct. >> in addition to those findings from the hospital lab, where there in the findings as included in your report. >> there was an incident the findings i believe there was coding which had been smoking, there was caffeine, there were evidence of prior marijuana use. i would have to look at the report pretty. >> to refresh your recollection. we could put on the screen just for the witnesses recollection exhibit 624. and then if you could positive findings portion. referring to your report now, describe the other findings with

respect to this case. >> so the additional finding was a compound app, that is actually a precursor to fentanyl manufacturing but it is also a - fentanyl, not probably mostly inactive but it was measured as part of an additional testing was requested by the county medical examiner. in urine findings, we had positive findings of abba noise and fentanyl from those not confirmed because they weren't in the blood. it followed that and then we also had a findings for opioids in the year and we were asked to confirm those and we found it concentration of morphine in the red of 86 nanograms per liter. >> sorry you are saying that you will found morphine in the

urine. is that right pretty. >> correct. >> was a found in the blood. >> no, it was not. >> and can a finding of morphine in the urine be indicative of a prior use in advance of the time of death. >> yes, i can. you can see morphine in urine for several days. depending on the dose and prior use pattern. >> and again, said because it shows up in urine longer than in the blood prayed. >> yes. >> so you tested both the hospital blood in the urine in kenya describe the findings in the urine with morphine and you're also discussing it the key findings in the hospital blood but they effect to the other findings in your part, can you summarize with the work and if they were significant at all. >> you mentioned campaign, which is present in any of us. encoding which is present in the

metabolite of nicotine, from smoking. and then kevin abba noise, thc, 2.9 nanograms per later in his breakdown products of hydroxy and thc in 1.2. and in the inactive carboxy thc 42. >> and when it comes to the thc findings, relating to canada but noise, when impact is that have pretty. >> are doing turbid that but given the nature of the samples, and also what happens with them because they go into the back so they can be released slowly over time. anything like cpr could potentially release thc from the fatso and doesn't really mean a whole lot other than it was used at some point in time pretty. >> so i can made in the system

and be detected for some time. >> yes. >> so we can take the down thank you. as part of your testing process at the lab, with their also some metabolite or other substances that were detected as part of the testing buffalo the lab reporting limits pretty. >> we did find substances that were below the threshold of two report. and that is why they're not on the report. they are part of the data package that was requested and one can see those there pretty. >> do you keep those litigation packages with that date as part of your standard operating procedures of the court business at ms as bat labs pretty. >> all of the data in the litigation packages actually pulled from that data on request but yes. >> so as part of the testing of the lab testing of the samples in this case, i would like to ask about the testing process for methamphetamine and whether

there were findings of amphetamines unit. >> so when we test positive for methamphetamines, at the - and anything that is positive about 81300 certain professional by that procedure is been confirmed by an alternate procedure. in this case methamphetamine is positive in the screen and then we ran the confirmation test for amphetamines. in particular the test consisted of ten compounds. but were only interested in the larger compounds that were actually confirming in this case. so in this case we did check for kevin for the main and because of catalyzing, there was evidence of impediments but below the reporting limit so it was parted. >> and you recorded that. and does that mean that the body breaks down methamphetamine into

and can mean overtime pretty. >> yes. >> in addition to confirming the presence of amphetamines, was there also an indication an on initial testing for morphine. >> there was an indication on the time-of-flight screen but because it was below the reporting limits, it was not confirmed nearly hundred barely an education pretty. >> that just means it didn't go through that second process. >> yes. >> typically describe for opioid therapy for people that are going through opioid treatment. >> and other components of it, also in the lockdown pretty and it's an essentially a generic narcan. >> yes. >> getting back to the blood communicated that was hospital blood.

correct. >> what is significant for that pretty. >> will hospital blood if it is more rep. of what is actually circulating in the body prior to the time of death. after death, there are changes that occur was hard concentration that particularly an essential blood collected from heart. that's a post more than distribution with the drugs go from areas of higher concentration to lesser concentrations. that wasn't an issue, such as blood but it can still occur. ideally you would try to get a sample is close to the time of death as possible. >> were some samples taken after death. can there be some postmortem redistribution.

>> i think that is possible parted it is a lot we don't know is certainly is possible and intends to increase concentrations rated. >> when you say increased conservation is having the level or higher than it actually was at the time of death. >> correct. >> what about how wallace's pretty. >> that his breakdown of the red blood cell. >> and did that have any impact on the testing in this case. >> no, that would have impact on certain clinical chemistry tests like potassium. the store the red blood cells when you analyze the blood sample for drugs, penalizing the whole sample. it would have no effect. >> so you mentioned that the lab received samples the day and thousands of samples a year, you compile data from the year 2020 with respect to conventional

cases methamphetamine cases with us help you conceptualize the results in this case. >> sure. >> for demonstrative purposes, exhibit 920. [inaudible]. [inaudible]. >> what was the number again. >> i'm 20. >> if we could publish.

[inaudible]. >> thank you, your honor. doctor, i'm going to have you describe what is shown on the screen. >> as of right now, we are looking at what happened when the levels metabolize over time. so gradually, the amount of fentanyl start to increase. [inaudible]. >> and that is what would happen is it metabolizes fentanyl. >> correct. >> can you describe what is shown here pretty. >> so this is data from the labs from the year 2000. we look at the fentanyl concentrations in postmortem

cases specifically in those and only those, that were collected in non- peripheral blood for the reasons that i mentioned before, cardiac blood can have a significant postmortem distribution so we wanted to have her look at samples at a minimal amount of that. >> this was in the year 2000. with this from 2020 pretty. >> that was my mistake, it is 2020. this was the year 2020 printed we had 19100 - cases that we looked at and in studies postmortem cases, the mean concentration or average is 16.d in the median concentration was ten, median being about 50 percent above and 50 percent below. >> and with respect to the peripheral blood you've indicated that you chose the samples that would have minimal post morning distributions. why is that.

>> because the sample that you have from the hospital blood he is probably going to have less issues of post morning redistribution had invented postmortem blood. >> and in these cases that are represented postmortem cases, these cases that you would be getting from offices of the coroner's office pretty. >> correct. >> where they are deceased or dead. >> correct. and also for the concentrations, those were 6.01, the means the median data 2.2 nanograms per meal the ability to predict. >> just a clarify. with respect to these cases, the average levels of fentanyl was 15.8 nanograms the average level for 6.01 handicraft per milliliter. >> correct. >> what is shown here printed. >> so this slide shows postmortem cases and again for

the year 2020. so out of those 90185 cases we had 15455 that included fictional and more fentanyl but there was 3,071,204 cases with no more fentanyl. there were exceptions for that for reasons of testing purposes. but those ones that were only fentanyl. a. >> so the site indicates there was a significant number of this thousand 71204 cases where there was fentanyl but no more fentanyl et al. >> next slide please predict. >> so this is switching gears, we are looking at the duis driving under the influence hotel concentrations that we founded in 2020. so these are blood samples there sent to the labs needed for the people that were suspected of driving under the influence of drugs.

and also potential of the reasons the way they were driving. in this case we tested 2345 cases that were individuals that were alive. and other drugs may be present but this was specifically looking at fentanyl winning concentration of 9.5 nanograms per milliliter 5.3 and the norfentanayl of 5.42 in the medium of 2.2 pretty. >> just to clarify, please 2345 cases, those individuals were alive is that right pretty. >> correct. >> and the average fentanyl levels were 5.9. >> yes. >> and the average norfentanayl is 5.4. >> yes pretty. >> next slide please. >> so this is just a break it

down of the fentanyl concentrations we found it in the drivers were alive read so almost the majority of them were under 5 nanograms of fentanyl. we had another 26.3 percent between 5.1 and 10 nanograms per milliliter in the next set of data was led to her sitting cases which were between 11 and 15 nanograms. so that would be the same. that mr. floyd's level of 11 nanograms. that we had quite a few cases that were even greater than that. we had about a hundred and nine between 16 and 20. anyone between 21 and 26 and then we actually have 53 cases in subjects where it was greater than 50 nanograms per milliliter. >> comparing mr. floyd's level to the driving population, the individuals were alive, his

level was within a quarter of the pie the dui cases the lab received pretty. >> will be right in their grade yes. >> and you indicated that those levels for drivers were found in 53 cases higher than 60 nanograms per milliliter. as of those individuals were alive advantage when driving at the time pretty. >> yes. >> so this is basically concentration and samples blood samples that were submitted by mr. tran five and we found fentanyl and 11 nanograms milliliter. >> next slide please.

>> so this slide shows what the ratio of the parent drug is an 11 grams divided by 5.6 for the >> subdues the show in which the way that you would calculate it. next slide please. let's start on this slide pretty. >> so the slide shows the ratios of fentanyl levels between nine and 13 nanograms per milliliter so that range was chosen because mr. floyd concentration was 11 nanograms per liter and when we do driving under the influence work, we actually assign an uncertainty of measurement to that result. so if the driver had an 11 met nanograms present we would report that is 11 nanograms plus

or minus 2 nanograms per milliliter. so i did this to see what kind of ratios do we see between postmortem in dui cases in the fentanyl levels is between nine and 13, the kind of ratios that we see. and we can see in the postmortem cases, mean ratio of fentanyl and norfentanyl was 9.05 with a median of .8. versus the dui population remained was 3.2 and 2.24. >> just to clarify, in the bar that shows the postmortem cases, without 3088 cases that you look at between the range of nine - 13 milliliters. >> yes. between nine and 13 pretty. >> the ratio was .05 on average is that right pretty. >> correct. >> with respect to the dui cases, cases between the range of nine and 13 are milliliter,

the right. >> correct. >> so the average ratio is 3.20 rated. >> yes. >> how does mr. floyd's ratio compared to that data set rated. >> so george floyd's ratio is roughly just a little bit below the median ratio in dui so postmortem cases we know that are fentanyl concentrations, would be much higher than the norfentanyl because of the frequent, these are deaths due to fentanyl. other drugs may be present they can be other reasons for that debt, doesn't say this is only intoxication but just looking at it as a whole, large amount of data is what we observed. we know with the dui population, they are alive but of the drugs may be present as well. so it's really just sort of looking at how things look differently in the postmortem population predict. >> and this site also shows that

mr. george floyd's a ratio with the average and even below the median for that found in the dui cases. >> yes. >> next slide please. >> so this slide is actually sort of a summary of a previous slide but it basically shows the relationship between fentanyl and norfentanyl and between postmortem, the dui cases and mr. george floyd freighted. >> and it shows how the norfentanyl levels increases over time over the fentanyl levels. >> and metabolizes. >> next slide please. you also look at data with respect to methamphetamines for 2020 and the meth lab. and what is shown in the slide as of right now predict. >> this slide shows concentration of methamphetamines found in mr. george floyd's hospital sample, it was 19 grams per milliliter.

and as we talked about earlier, and had me was below the reporting limits. so it was not reported. ... ... we had 3271 cases that had methamphetamine driving under the influence. 2009, 75 included amphetamine 296 were methamphetamine. >> we are talking about the dui population, individuals 3271, individuals who are alive. >> next slide.

>> this is a further breakdown of what we see in methamphetamine cases. the concentration and all dui cases was 378 of methamphetamine. median was 240 nanograms a milliliter and in the five to 25 range was five, being the lowest, we had 192 between five to 20 milligrams a year which is in the range of mr. ford's methamphetamine. >> mr. place level was 19 nanograms a millimeter? >> yes, it says on the bottom and again 94% dui cases mental contrition. >> mr. .9%. >> correct. >> next slide.

what is shown? >> this is a further breakdown of what methamphetamine concentrations we've observed in drivers in the past 2020 and again other drugs that may be present in this case we had 196 cases between five and 20, 360350. 571 between 101 to 200. 578 between 501 and 1000 and an additional 215 cases methamphetamine was great. >> again, you had to 15 cases where the number was greater than 1000. >> correct. >> the biggest piece, 30.9% cases were between 201 and 500 grams a milliliter. >> yes. >> mr. flights level was

exceptionally low? >> in relationship to the dui, yes. >> nothing further, your honor. [background noises] [inaudible] are right, it's a little unusual for you to testify in a death case, is it not? >> not terribly, i do work with medical examiners specifically are the ones to testify cause of

death, usually i'm involved in a death case, it's usually growth resulting in death. >> so you work in a laboratory that works with medical examiners from your own country? >> correct. >> you perform these services in a variety of different contexts? do not just. >> so you testify some are clinical in nature, some are law enforcement in nature, some are death related? >> correct. >> at the time you became involved in this case, you are obviously aware of the significance. >> yes. >> your laboratory goes through an accreditation process? >> we do. >> part of the accreditation process is to establish standards and reporting?

>> yes. >> so the reason i laboratory will have the threshold is to be consistent in how toxicology is reported to various ways? >> correct. >> one of those accreditation standards is to have and set this of a particular chemical component below the threshold, he would suggest it on the report? you are saying not there are instances where medical examiner if something was present at the lower threshold and depending on what the situation is, it could be reported as such, not common practice. in this case from. >> it is not common practice to report things that are below are chemicals below the threshold

because it's contrary to the accreditation standards, agree? >> it does depend on the situation but by and large, if there is a reason we have cutoffs, we go below those, it's basically not something we would typically do. >> so an analyst comes in hypothetically and when you see certain markers have an indication thing, that would be because of the accreditation. >> i'm not quite sure i understand hypothetically comes in and a question is presented about the presence of a particular substance, the substance was below the

threshold -- >> your honor. [inaudible] >> it's a hypothetical. the analyst acknowledge the possibility that would hypothetically be because of the threshold rules rex. >> i really can't speak about the crime lab because i don't work in the area so to me limited to toxicology and analysis blood or urine. >> so in other words, the reason we have these thresholds is the we set the rules, right reasons the thresholds were established

has to do with validation will. thresholds are not set because of any it's what you have to use as a threshold, laboratory establishes those in right in accordance with validation. >> sop being standard operating procedures so if the laboratory states this standard and says here is the standard and then does something or reports something against that standard, that would be a violation standard operating practice? >> if it were reported without affirmation, yes. >> a few follow-up questions to your testimony, he was met with or spoken with members of the prosecution team several times? >> yes. >> including february 26, march

5, march 12, april 5 and april 6? >> that sounds right, i don't know exact date. >> understood. >> he wouldn't disagree if i told you those dates? >> correct. >> summaries of your conversations. >> correct. >> onto make sure i understand the difference between fentanyl and north. you would agree fentanyl is the active ingredient when you report the fentanyl concentration, the active ingredient? when a person and just essentially any substance, controlled substance, doesn't have to be an illegal drug, the body metabolizes that? >> correct. >> the body eliminates that? >> yes. >> through natural processes of the body. >> yes. >> the elimination of the substance results in a metabolite?

>> yes. >> fentanyl, being the active ingredient, nor federal is the top? >> correct. >> in this particular case you discovered fentanyl concentration of 11 nanograms a milliliter? >> yes. >> a level of 5.6. >> yes. >> you testified on direct examination that that could be one of two scenarios occurring? >> yes. >> one scenario is that a person took a certain amount of a -- fentanyl and enough time has passed to eliminate that, correct? will break it down into a metabolite. >> that is one. >> the other scenario is someone took some, the initial dose began to break down and the

person took more so the active ingredient there but had not yet broken down, right? >> correct. >> so it either -- you described i think as an acute ingestion? or non- acute ingestion when you have fentanyl, fentanyl will break down more fentanyl but still take more fentanyl so you can take it while the first fentanyl was breaking down? >> correct. >> put into context of people who may consume alcohol, i have a beer, my alcohol concentration will rise to a certain level, right? based on the alcohol concentration, agreed? >> yes. >> my body immediately decrease eliminate alcohol. >> correct. >> i have a second fear, i add

more alcohol was in my blood alcohol concentration to rise, correct? >> yes. >> that's similar with all substances including fentanyl? >> in general, yes. alcohol at a fixed rate over time, there's only so much you can eliminate, some drugs are a little. >> some may be faster, some may be longer. when you describe the results in this particular case, you're talking about -- i'll straighten that out, sorry. based on a strict interpretation of test results, there's no way to determine at what time in a particular amount of fentanyl was adjusted, agreed? >> i would agree. >> fentanyl, being a toxicologist is a lawfully manufactured controlled substance in the united states.

>> it can be described backpack, lollipop, they can put it in lollipops. >> the fentanyl contain in a patch or lollipop, by an anesthesiologist is in a controlled manner? >> yes. >> when we are talking about illicit drugs that include fentanyl, you have no way of knowing what the particular fentanyl concentration is filled to fill? >> yes. >> every single pill you take becomes a unique experience for the person, right? >> that's true. >> regardless whether you have tolerance or non- tolerance, any single incident can cause adverse reaction? >> for sure, if somebody had a pill ten times fentanyl that another, then yes. >> and you have no idea?

because they are not manufactured in a controlled environment. >> yes, sir. >> in terms of to understand there were some pills on the floor of the squad car? >> that is my understanding, yes. >> the pills were tested containing the dna of george floyd? >> i heard that, yes. >> presumably the pills were not in there prior to mr. floyd being in the squad car, right? >> i assume not, yes. >> so you understand they were tested, appeared to be partially ingested or dissolved?

>> okay. >> so there would be evidence of acute ingestion of fentanyl and/or methamphetamine at the time mr. floyd was in the backseat of the squad car? [inaudible] >> sustained. >> are you familiar with the term hooping? [inaudible] >> answer if you know. >> i don't. >> in terms of your slideshow, i don't have the electronic copy of it, some follow-up questions,

you reviewed in 2020 a total of 19185 fatal overdose cases, right? >> they are not necessarily fatal overdoses, they were cases from medical examiners we found fentanyl in their blood sample but they could happen homicide or other drugs involved so they were just random fentanyl concentrations. >> catch you. >> -- somebody may have been shot and killed as a result of a gunshot but as a result of the autopsy process, they collected the blood analyzed the blood as part of the normal autopsy process? >> correct. >> the cause or manner of death in a gunshot wound, homicide, we still look at the blood.

>> is. >> a total of 19185, right? >> correct. >> when the slide says 19185 fatal overdose cases, you are suggesting it's misleading because you're suggesting a fatal overdose case? >> i didn't get said that that was something i corrected the other day and said it's not correct. >> okay. >> i apologize, he says fatal overdose cases, that is not correct.

[silence] [silence] >> we are going to take a 20 minute recess, which going to do a little work in the break but 20 minutes

>> any light to shed on this? >> what's going on. >> i received stamp 49606 and apparently i printed it and started working on my preparation and apparently i received an updated copy of this presentation and its 49623 so it's like 17 page later when trying to verify when i received it because i was using this in preparation of this was all last night. >> was all provided, i'm not sure if it's the same batch that went out but obviously the witness made updates, an updated slide for the jury.

>> i understand, mr. nelson has an earlier version, the updated version. >> show the updated version. >> correct. >> when was the updated version sent? >> the same day as the original -- [inaudible] [inaudible] >> we are going to just take our break. there's a lot of moving parts, i don't think anybody -- we can just acknowledge, without showing it again, you've shown earlier versions.

>> fine and part of the problem we are experiencing here, i'm getting many of these items in pdf format, some are electronically from so many people involved, getting things in different formats so if i could have a second. >> yes, it seems like a good, nobody should be criticized oregon, just tell the jury this is what it is. >> i could provide an extra copy and read publish the slides presented we want to make sure we are not presenting information that's inaccurate. >> it is my fault, your honor.

[inaudible] >> i must have looked and assumed it was a second copy of the same thing. >> tell them you were relying on an earlier version of the one witnessed showed. >> perhaps it would help if i could give, get a copy of the. >> until we are done with the break, let's reconvene, where are we at now? 2:45 p.m.? 3:40