♪ ♪ welcome to inside politics, i'm john king. we're in a quick break but moments away from resuming the trial of derek chauvin in minneapolis. it is day ten of testimony. and it began this morning with more expert medical perspective on exactly what killed george floyd back in may. a forensic pathologist. dr. lindsay thomas ruling out suggestions by the defense that mr. floyd could have died from a

heart attack or from a drug overdose. dr. thomas clear, the police on trial, the officer on trial, in her view, is the cause of mr. floyd's death. >> what it means to me is that the activities of the law enforcement officers resulted in mr. floyd's death and that specifically those activities were the subduel of restraint and neck compression. >> to discuss is cnn senior legal analyst laura coates and our law enforcement analyst charles ramsey. thank you both for being here. laura coates, this medical testimony, part of the prosecution build, the medical examiner, we believe, will come next. your perspective on how the prosecution is building its case? >> they're doing a great job of it. they're building off and corroborating from prior testimony. you're seeing and hearing from the bystanders first, talking about law enforcement. they pretty much covered the idea of this was an unreasonable

amount of force to use. now they're in that substantial causal factor and they began with that dynamite testimony yesterday of the pulmonologist who described with great detail that george floyd was struggling to the point he tried to use his body, his fingers, his knuckles, his face to lift himself. now you've got this particular forensic pathologist whose job it is to determine and evaluate the cause and manner of death, corroborating, showing through autopsy photos not published to the general public the way in which the pulmonologist's -- bruises on george floyd's body and ultimately concluding that even with the underlying medical conditions she says he died as a result of the law enforcement's actions against him, not talking about anything about fentanyl or anything else, honed in on what

she saw through the video, which normally doesn't happen. they usually only have the body before them and a process of elimination. they've got 9:29 to have looked at the actual death that occurred and they used that. >> and chief, dr. thomas was in the hennepin county medical examiner's office back when the next witness we believe, the current medical examiner was in his training. so the prosecution making a choice to bring in a more experienced person beforehand. dr. tobin yesterday, dr. thomas today and i heard you talk about this earlier and i think it's important. it is difficult for the prosecution, and for these medical witnesses, to present what can be highly complicated, highly scientific data, and conclusions in a very conversational way. i want you to listen here, this is part of the testimony where the prosecution trying to make the point. they know what the defense is going to say, trying to get the expert witness to say, no, mr. floyd died because of what the police did. listen. >> do you agree with dr. baker's

determination on the cause of death? >> yes, i do. this is a death where both the heart and lungs stopped working. and the point is that it's due to law enforcement subdual restraint and compression. the activities of the law enforcement officers resulted in mr. floyd's death and that specifically those activities were the subdual of the restraint and the neck compression. >> in both the questioning and the answers, sort of short, succinct english, accessible testimony. >> you're right. this case has been building from the very first witness. it was largely emotional with the first few witnesses, you know people that were actually on the scene started gradually getting more technical with the police experts, the trainers and the police chief and so forth. now you're getting into the medical aspect of it which gets, you know, very technical, can be very dry and can be very hard to understand. but the prosecutor, mr.

blackwell in particular, has done such a good job of walking us through it by asking the right questions and getting the responses in a very understandable way. and in bite size chunks so that everyone can understand it. i mean, yesterday i found myself feeling my neck and so forth when dr. tobin was going through his testimony. i think it's very, very powerful and it's really building up. i don't think the prosecution could do much better if at all than what they've done thus far. >> it's very compelling, laura, from a story line, a sad and tragic story line, but compelling in how they are presenting it. but it's very strategic in that they understand mr. nelson's defense arguments. mr. nelson will get his chance. so one of the key strategies is to get the jury to make up its mind about what they expect to hear from the defense. we know the defense has argued with other witnesses, mr. floyd was using drugs, he had high levels of drugs in his system

and that's what caused the co 2 failure and for him to stop breathing. this witness this morning saying no. listen. >> you reviewed the toxicology. >> yes, oh, yes. >> how would you characterize the amount of meth in mr. floyd's system? >> well, it was there. it's not particularly high. certainly in deaths that i have attributed to methamphetamine, it's been much higher. but it's not like there's any safe level of methamphetamine. but this was a very low level. >> so was the methamphetamine significant in your assessment of the cause of death? >> no. >> laura coates, just your take on how they have presented not only their case but essentially tried to get out ahead of the defense case? >> again, very compelling here, but remember, they're not just up against the defense's team in their ability to try to anticipate it. remember, the idea of this pathology report, the toxicology report, the drugs in the system,

has been an issue for a very long time. even before the jurors were even sworn in, before there was a jury questionnaire, the idea of there being more than one autopsy report, one by the hennepin county medical examiner's office, one by the family, had in the minds of a lot of people, there was something wrong with the medical examiner report that somehow it was jaded, it was biased in some way. they're also having to resolve a previous thought about this autopsy report, and anticipate the defense -- >> laura coates, sorry to interrupt. the trial is resuming. >> we want to resume our discussion on homicide after that. just to clarify for the jurors what these various classifications are, if we talk about natural, you discussed that with us. >> yes. >> an example of a natural manner of death would be, for example, a heart attack? >> yes. >> if we talk about an accidental cause of death, where

would drug overdose fit in general as a cause of death? >> usually drug overdoses are accidental unless there's evidence of intent in which case it would be suicidal. >> so we know what suicide is. >> yes. >> and undetermined. if the medical examiner can't tell which have these it is or what it is and undetermined is what you would indicate? >> exactly. >> so if the manner of death here has been determined to be homicide, does that, in your opinion as a medical examiner rule out a death by accidental drug overdose? >> yes. >> now let's go back to exhibit 952. let's commit it for demonstrative purposes.

doctor, you were talking about the designation of homicide. >> yes. >> and tell us what this guide is as relates to how we define homicide as medical examiners. >> homicide is defined in its most broad sense as death at the hands of another. and it goes into more detail if we wanted to look at that. >> yes. so if -- but this is guidance given from the national association of medical examiners to medical examiners. >> exactly. >> and it provides guidance and guidelines on how to designate a manner of death as homicide? >> yes. >> so if we could go to the next slide. so doctor, could you read this for the record. >> homicide occurs when death results from a volitional act committed by another person to cause fear, harm or death. intent to cause death is a common element but is not required for classification as

homicide, more blelow. it is to be emphasized that the classification of homicide for the purposes of death certification is a neutral term, and neither indicates nor implies criminal intent which remains a determination within the province of legal processes. >> and you agree with this? >> absolutely. >> it's a guideline you follow? >> yes. >> and have you followed this kind of a guideline for the years you've been a medical examiner? >> yes. >> is there more guidance given from the national association of medical examiner guidelines on what constitutes voluntary acts? >> yes. >> if you could click one more. dr. thomas, could you read this for us. >> in general if a person's death results at the hands of another who committed a harmful volitional act directed at the victim the death may be considered a homicide from the

death investigation standpoint. and then although there may not have been intento kill the victim the victim died because of the harmful, intentional, volitional act committed by another person. thus, the manner of death may be classified as homicide because of the intentional or volitional act, not because there was intent to kill. >> and when you agree with the conclusion that dr. baker reached of homicide, is this the definition of homicide that you're applying that we saw in these two slides? >> yes. >> thank you, dr. thomas. now i want to ask you about a new subject. and this has to do with certain studies that assess whether the prone restraint is dangerous from a breathing point of view. and i'd like to get your

perspective as a forensic pathologist and medical examiner in this respect. are you aware of any such studies? >> yes. >> do you agree generally with the research that comes to a conclusion that the prone restraint is not dangerous for respiration? >> in certain laboratory safe settings that may be true. but i do not agree with their applicability to real life situations. >> if you could generally characterize for the jurors, what's the punch line of these studies, what do they show in a. >> they purport to show that putting someone in a prone position, even with some restraint and with weight on their back is perfectly safe. >> do you find the studies to be reliable or do you find them to be controversial? >> well, i think they are fine

for laboratory purposes, but they bear no resemblance to real world situations. so i would say they're irrelevant for purposes of what we're talking about here. >> and so how do they then not relate to the real world? what's artificial about them? >> well, i would say for starters these are volunteers who have agreed to be put in this dangerous position of a prone restraint. but they know perfectly well at any point if they feel scare or uncomfortable all they have to do is say stop and that has happened in some of these studies that a couple of the volunteers have said no, i can't tolerate being in this position, it's too scary. that, to me, immediately takes out that whole element that we were talking about about the terror, the physiologic stress. that's number one.

number two, is they are healthy volunteers. these are young people who have mostly young people, mostly healthy who have agreed to be part of this study. so it doesn't relate to someone who may have other underlying factors that may contribute. thirdly, there's -- they're put on a gymnastics mat to be down so completely different when you're squished between a person and the hard ground versus having an evenly distributed weight on your back and you're on a mat. third, none of -- or fourth, i guess, and perhaps most significantly here, none of them went on and on and on beyond the point where the person stopped breathing and where their heart stopped, so they were being

monitored the whole time. and if at any point they had had significant respiratory or cardiac difficulties the study would have stopped and the person volunteering knew that. so it -- to me, it bears no resemblance to what mr. floyd experienced. >> did any of the studies involve a knee on the neck of any of the volunteers? >> no. >> any of them go on for as long as 9:29? >> no. >> do you know if any of the studies actually measured the decrease in lung volumes as part of the study, that is decrease in oxygen reserves? >> not that i know of, no. >> so any relevance to george floyd at all? >> not in my opinion, no. >> so dr. thomas, have you done any calculations or kind of work of your own to measure what the

subdual and the restraint with the knee on the neck and the back of george floyd would have done to his oxygen reserves, or lung capacity? >> no, that would be something i would completely defer to a pulmonary doctor to address. >> so then are you able to tell the ladies and gentlemen of the jury if you haven't done that work whether the forces that mr. floyd was subjected to would have even killed a normal healthy person? >> in the way you phrased that, not based on lung volume and that kind of study. i mean, from watching the video i certainly wouldn't want to be in that position but that's a different answer. >> thank you, dr. thomas, no further questions. >> mr. nelson.

>> morning, dr. thomas. >> morning. >> how are you today? >> good, thank you. >> nice to see you. >> you described being a forensic pathologist of being the doctor's doctor. >> general pathologist is considered that, yes. >> and the forensic pathologist in terms of a death investigation, you kind of have po wear many hats, right? >> yes. >> you have to have a broad familiarity with multiple medical conditions, right? >> yes. >> and sometimes medical conditions may appear at autopsy that you've never seen before. >> yes. >> right? some strange disease that you've never seen, right? >> yes. >> and you have to -- you will speak to other doctors, right?

>> yes. >> you will gather information and share that -- they'll share information with you to help you conclude -- make conclusions in an autopsy, right? >> yes. >> and you also described how being a medical examiner is more than just the autopsy. right? >> yes. >> the autopsy is one small part of a death investigation, right? >> yes. >> you described reviewing videotapes in certain circumstances, right? >> yes. >> past medical records, right? >> yes. >> interviews with friends, family members, people who were -- who knew the decedent. right? >> yes. >> and ultimately the medical examiner's office compiles a massive, you know, amount of information itself about the cause and manner of death. right? >> yes. >> and you've had an opportunity

to review a lot of that information in this case, correct? >> yes. >> now, have you reviewed all of the interviews of witnesses? >> probably not all of them, no. >> have you -- after you prepared your report, have you been provided with additional materials that may be relevant to your considerations? >> not that i can think of off the top of my head. >> okay. and we'll come back to that. so i just kind of want to -- but you did have an opportunity to review dr. baker's entire file, correct? >> yes. >> and i believe we'll be hearing from dr. baker later this morning or this afternoon. but we'll have some questions for him. i would like to follow up on some of your conclusions.

there's a term used in dr. baker's autopsy, the cause of death, the term complicating. >> yes. >> can you define medically speaking what the term complicating means? >> oh, i guess it could be used in lots of different ways. the way i would think of it in this setting is both things were present, that there was a cardiopulmonary arrest and that it was due to law enforcement subdual restraint and compression.

i guess that's how i would consider it in this setting. >> have you been provided with dr. baker's -- any information about dr. baker's opinions in this case? >> nothing very specific. i mean, just what he put in the autopsy report and all of his conclusions. >> so in terms of the word "complicating" it's capable of different definitions based upon the forensic pathologist. right? >> yes. >> and so you as a forensic pathologist may have a different interpretation of what complicating means compared to dr. baker, for example? >> yes. >> and there's a reasonable degree of disagreement amongst -- in any case generally, it's reasonable for doctors to disagree with each other. is it not? >> that sometimes happens, yes. >> all right. you did not perform the actual

autopsy of mr. floyd. correct? >> correct. >> and that was dr. baker who did that. right? >> yes. >> and you know dr. baker well? >> yes. >> and you know him to be a competent medical examiner? >> yes. >> he's the chief medical examiner for hennepin county at this time? >> yes. >> now, you were provided, again, with all of the information from his report, and i would like to go through a few of the things with you. let's talk about mr. floyd's heart first. >> okay. >> what was the size of mr. floyd's heart as measured at autopsy. >> the weight of mr. floyd's heart was 540 grams. >> okay. and would you explain or would you describe that as an enlarged heart? >> i would say it's a slightly enlarged heart, yes. >> and there are some different measures of how to base an enlarged heart, or how to determine if a heart is

enlarged. right? >> right. by some categories, that heart would not be considered enlarged. >> so there's two, as i understand it, two different kind of primary measurements, or primary ways of comparing mr. floyd's heart to determine if it's enlarged. right? the molina studies and the northwestern studies? >> oh, oh, i see, oh, there's probably multiple ways of looking at heart weights. i mean, those are two of them. there's the study from the mayo clinic. there's one in europe. yeah, there's lots of ways of analyzing. >> but ultimately based on all of your information you would agree that mr. floyd's heart was slightly enlarged? >> yes. >> in terms of the demyoand

molina standard what would a male heart weigh for a person similar to mr. floyd? >> i don't know off the top of my head. >> would you disagree if i said it was 583 grams. >> that well could be. for the average. >> for the average, right. >> yeah. >> so according to -- if that were the average heart rate -- or heart size, excuse me, heart weight, 383 grams relevant to mr. floyd's heart, mr. floyd's heart would be considered profoundly enlarged. >> well, the thing about using averages in -- especially medicine, which is of course what i'm most familiar with, is we don't generally say -- we don't generally just compare it to an average. we compare to an average plus or minus two standard deviations. that's why the range that i

usually use is, you know, from 253 to 510 grams would be the range of normal for someone of mr. floyd's height. and so i don't know in the demyo-molina study what their two standard deviations would be. i wouldn't use just the average. >> so in terms of your -- how you would assess the weight or size of the heart, you would say 510 grams is the high -- 510 grams is the high end? >> right, right. >> of that. and 540 is -- exceeds that, right? >> right. >> and so in terms of whether it's a very enlarged heart or even a relatively minimally enlarged heart, a larger heart requires more blood. right? >> yes. it has greater demand, yes. >> what are some of the things that cause a person to have an enlarged heart? >> probably the primary cause is

high blood pressure. >> and you understand based on mr. floyd's medical records that he did, in fact, have a history of high blood pressure, correct? >> yes. >> can you describe the blood vessels of the heart? >> there are several major coronary arteries that as i mentioned supply blood and nutrients to the heart muscle. there's the left and right. and then the left branches into the left anterior descending and the left circumflex and then there's some other ranges off that. >> how would you describe narrow ing or stenosis of the coronary arteries. >> the way we as forensic pathologists describe it, we look at an opening. if an opening is fully open, then that would be 0% narrowing, and if it's completely closed then that would be 100% occluded. and so then we look at anything

ranging from, you know, 25, 50, 75, 90%. obviously it's just an eyeball estimation. we don't actually get out c calipers and measure because the actual percentage doesn't really matter. it's more, do they have coronary artery disease? was it pretty good, pretty bad? that sort of thing. >> can you describe the difference between proximal and distal narrowing? >> the way the coronary arteries supply blood to the heart, they come off the aorta, which is the main vessel that takes blood from the heart to the rest of the body. and so in close to the aorta is called proximal to the aorta and then the further out it goes, distributing blood along the way to the heart muscle is called distal. >> when you have proximal narrowing how does that affect the heart?

>> it can narrow the blood supply to more of the heart than if you have distal narrowing. >> another way of saying that would be it decreases the amount of blood the heart is getting. right? >> yes. >> and it also affects how things are removed from the heart? or carbon dioxide. >> well, that's different. that wouldn't happen from the blood vessels coming in, i don't think. so i wouldn't include carbon dioxide in that. >> okay. is there a standard within forensic pathology where pathologists would consider to be that there's enough of a narrowing to cause sudden death? >> so the way i would describe

that is anything over more than 70 to 75% is in the view of a forensic pathologist something that in the absence of another cause of death could be used to explain death. >> okay. >> now, it's also true that people live with 100% occlusion, and go on and do fine. so you have to understand this is strictly my perspective as a forensic pathologist and everyone i see is dead. so that's kind of a different perspective. >> can you explain what myocite necrosis is. the cyte means cel, and myo means muscle. so when you have a heart, myocyte, it's the heart muscle cell and necrosis means death.

so if you see myocyte necrosis that means there are dead harass mu heart muscle cells. >> do you have to have that to cause sudden death. >> no, you don't have to have myocyte necrosis. >> hypoxia of the -- >> yes. >> can -- by other means? >> hypoxia means low oxygen. sorry. and your question is, can low oxygen to the heart cause sudden death through an arrhythmia? i presume? yes. >> how would you describe the conduction system of the heart? >> the way the heartbeats, the lub dub, is that there are electrical currents that go

through the heart muscle. and normally there's a certain sequence in which the heart muscles will fire and that's called the conduction system through which the electrical impulses flow. and that's what keeps the heartbeating in a regular rhythm that beat beat beat. and yeah. that's the conduction system. >> so what happens if the conduction system is impaired? >> then you can get what's called an arrhythmia, or abnormal beating of the heart. >> and that can result in sudden death? >> it can, yes. >> which artery is -- supplies that kind of pacemaker of the heart? >> oh, it probably is variable from person to person. i mean, i think the coronary artery that we consider the most important, usually, is the left

anterior descending coronary artery, but there's a lot of individual variability. >> can you -- what about the right coronary artery? >> that -- i mean, it just -- it really depends on any given person which part of the heart is supplied by their particular distribution. >> and in mr. floyd's autopsy the right coronary artery, dr. baker, determined had a 90% occlusion. correct? >> 90% narrowing, yes. >> when someone is exerting themselves, does that make the heart work harder? >> yes. >> does that mean that more blood oxygen, it needs more blood to function, the heart needs more blood to function at that time? >> yes. >> it's kind of like when we think about exerting anything, like jogging, running, the heart

needs more blood and hence more oxygen in order to function properly. right? >> yes. >> you also described the fight or flight kind of a -- the physiology of that in your consideration. >> yes, the physiological stress. >> and the physiological stress produces adrenaline. right? >> yes. >> and that also causes the heart to work harder? >> yes. >> and therefore need more blood? >> yes. >> and more oxygen? >> yes. >> so let me ask you this, in this particular case, right, we have a heart that is at least above average, right, needing more blood, we have a heart with a occluded right coronary artery, right. >> narrow. >> narrowed. we have a heart that the left

anterior descending artery also had a 75% narrowing. right? >> yes. >> and so you have -- and then you have an exertion of stress-producing adrenaline. right? >> yes. >> so the heart has to work very, very hard in this case. fair to say? >> yes. >> let's take the police out of this and i'm going to ask you a hypothetical. let's assume you found mr. floyd dead in his residence, no police involvement, no drugs, right, the only thing you found would be these facts about his heart. what would you conclude to be the cause of death? >> in that very narrow set of circumstances, i would probably conclude that the cause of death was his heart disease. >> so have you as a forensic pathologist ever certified a

death due to arthero sclerotic cardiovascular disease? >> thousands of times, yes. >> with similar narrowing of arteries. >> yes. >> have you ever certified a death due to hyper tensive cardiovascular -- >> yes, absolutely. >> with a heart at this weight or even smaller? >> well, if it was, again, in this setting where that was the only abnormal finding, then i would probably go with that, yes. >> so one of the things that has to be considered in this particular case is mr. floyd's heart. right? >> yes. >> and even without any sort of

an exertion, again take the exertion out of it, take the police out of it, take the drugs out of it, that's a potential cause of death that needs to be considered? >> yes. >> now, you discussed the abrasions that you saw and that the jury saw pictures of, you would agree that the abrasions are in a left to right pattern? >> meaning they're more on the left than on the right? >> right. >> on his face, yes. on his shoulder, yes. and then he had the abrasions on his right hands. >> and in terms of the pattern of the abrasion there's up and down -- an abrasion could go from the bottom of my body up or it could go from left to right. right? >> yes. i guess i didn't really focus on what direction the abrasions were going in that sense. >> okay. and that's fine. but you would agree that one

possible way that some of -- at least some of these abrasions occurred would be when mr. floyd was initially put down on the ground? >> i guess they could, yes. >> and not all of those abrasions necessarily occurred while mr. floyd was in the prone position, right? >> that's hard to answer. >> it's hard to answer when the abrasions were there. >> right. >> what caused the abrasions, right. >> right, right. >> and if someone was being held down with all -- with the weight of three people, would you expect those to be more punctile in their nature, you know with

the lines and movements? >> oh, gosh, there are too many variables there, i would say. >> okay. now, you ultimately determined that this case was an asphyxiation essentially. >> yes, that that was the primary mechanism. >> and asphyxiation is simply the lack of oxygen to the brain. >> yeah, inadequate oxygen. >> to the brain specifically? >> yes. >> and in terms of asphyxiation you would agree that there are multiple things that can cause asphyxiation. >> yes. >> so you use the reference to someone being strangled. right? >> yes. >> so if i came up to you and i strangled -- or i strangled a person, put my hands around their neck, there are certain things you would expect to see. right? >> sometimes you do, yes. and that's great when you do. you don't always. >> and those would be things like a broken hyoid bone.

>> yeah. >> the pe ticcihal hemorrhaging, and in asphyxia death there are frequently those signs available, right? >> it depends on the mechanism of asphyxia. >> so let's go back to the mechanisms of asphyxia. you described strangling. >> yeah. >> hanging could be one? >> yes. >> you've described positional or mechanical asphyxia. >> those are types, yes. >> positional being, you know, based on the position of the body, mechanical being something -- using some sort of a device to asphyxiate someone? >> oh, well, we haven't really talked about a lot about positional and mechanical. there's all kinds of things under both of those that can cause low oxygen. >> and one of the things that can cause, in this low oxygen to the brain, is the use of

controlled substances, correct? >> well, eventually, yes, yes. >> so someone can ingest a particular type of a controlled substance, that particular substance could affect the diaphragm, right? >> it affects -- some controlled substances affect the ability to breathe, which then decreases the oxygen, which then leads to low oxygen, yes. >> right. and that's essentially what you're saying is, is that there -- in this particular case, as i understand from my notes, is that essentially what happens is there was some event that happened that resulted in a decrease of oxygen to the brain, and that resulted in death. >> yes. >> and that's essentially what asphyxia is generally?

>> inadequate oxygen, yes. >> okay. and you were asked a series of questions about some studies in terms of, i think they're called a san diego. >> yes, dr. chan. >> are you familiar with the journal of forensic and legal medicine? >> yes. >> you testified that some of the problems with the chan studies were that they were in laboratory settings, sorry, laboratory settings, this they were controlled environments, healthy individuals, et cetera. right? >> yes. >> are you familiar with the work of dr. christine hall and her paper incidents and outcome of prone positioning following police use of force in a perspective consecutive cohort of subjects? >> is that the one from canada? >> yes. >> yes. >> and that was essentially an

analysis of actual police encounters. correct? >> yes, in canada. >> in canada, understood. but they actually -- that study, they go through and they look at the number of police citizen interactions, correct? >> yes. >> and then from those police citizen interactions they further go in to look at how many involved being placed in the prone position or a non-prone position, correct? >> yes. >> they consider various actual real life variables, agreed? >> yeah. >> and including drugs, whether drugs were on board, whether the length of time to a certain extent that someone was in the prone position, agreed? >> yes. >> and ultimately they analyzed about -- it was about 3,000 prone positional placements? >> yes. >> out of a total of like

1.1 million police interactions? >> yes. >> so 1.1 million police interactions resulting in about 3,000 prone position arrests, that those -- these are real people, real incidents, right? >> yeah. >> and in those 3,000 or so interactions there were no deaths that occurred? >> isn't that amazing? when you consider that virtually every forensic pathologist in the united states has probably had an officer-involved death like this. how did they -- it utterly baffles me which is why i kept saying canada because i think -- i don't know what's different. >> i'm going to object at this time as nonresponsive. >> so the -- let me ask you in

terms of hypoxia. can you again define hypoxia. >> low oxygen. >> and which organ is more sensitive to the lack of oxygen? >> the brain, absolutely. >> the brain is the most -- it needs the most oxygen, right? >> yes. >> and that's because it's doing millions of things simultaneously, right, agreed? >> yes, i'm sure there's lots of reasons metabolically why it needs oxygen. >> i think a previous witness said it needs about 20% of the body's oxygen supply to function. >> that sounds about right, yes. >> but the heart also needs oxygen, right? >> yes. >> so in terms of the professional standards for determining an asphyxia death,

is it true that you have to first exclude all natural and non-natural cases, or causes of death? >> well, you can have natural and non-natural causes of low oxygen. so i'm sorry, i guess i don't understand. >> sure, there's a criteria that's established for making a determination of asphyxia as a cause of death. right? >> well, i'm not really sure what -- i'm sorry, i just -- i don't understand that. >> fair enough. is the prone position in and of

itself inherently dangerous? >> not if there are no other factors. >> okay. so the prone position is examined and used in a lot of different settings, right? >> correct. >> even in hospitals in the treatment of, say, covid, the prone position is used. >> correct. >> and in those circumstances, being in a prone position is not inherently dangerous. right? >> yes. >> i mean, chiropractors put people in the prone position. right? >> yes. >> massage therapists put people in the prone position, right? >> yes. >> so the prone position, just talking generally speaking, no other factors, the prone position in and of itself is not inherently dangerous. right? >> right. >> is the prone position on

concrete inherently dangerous? >> again, with no other factors, as long as someone can breathe, no. >> i could be laying by the pool in florida on my stomach in the prone position, not inherently dangerous. >> right. >> do you know or did you take into consideration mr. chauvin's weight in your analysis? >> oh, i'm aware of his weight. i would say i took it into some consideration but it wasn't a major factor one way or the other. >> okay. you reviewed all of the videos,

right? >> yes. >> and it's fair to say that portions of his weight were placed on mr. floyd's body at a different distribution? >> yes. >> and ultimately in terms of the autopsy that dr. baker conducted, in terms of the area in the shoulders, the back and the neck, no bruising was found. right? >> right. >> in your experience as a forensic pathologist, if someone is placing a significant amount of weight on a person's area, for a prolonged period of time, would you expect to see bruising? >> you might or might not. it's so variable. >> and you would agree that there are no abrasions or bruising described in the autopsy in the neck area of mr. floyd? >> correct. >> there's no bleeding into the

muscles in his back, right? >> correct. >> you would agree that the knee is sort of a pointy or a more protruberant part of the body? >> i guess so, but kind of flat on top because of the patella. >> and when we talk about the shinbone itself, there's not a lot between the skin and the shinbone, right? >> that is true, yes. >> and it's sort of a triangular shape, right? >> yes. >> and, again, along mr. floyd's back there's no long bruise consistent with a shinbone, right? >> right. >> and there's no more circular bruise consistent with a kneecap?

>> right. >> you've reviewed obviously a lot of strangulation type cases in those -- in your career? >> yes. >> strangulation with the hands. right? >> primarily manual, but also ligature. >> ligature being like a rope or a thong cord or something? >> exactly. >> and in those manual strangulation cases the pressure that's exerted in that will frequently leave bruises, fingerprint size bruises, right? >> frequently, but not always. >> and ultimately what increases the likelihood of seeing a bruise is the amount of force that's applied, right? >> you know, i don't know what all the factors are, whether it's fragility of the vessels, whether it's the length of time,

whether it's the force, whether it's the location. i think there are lots of variables, and everyone bruises differently. >> so yesterday it depends on what medications they may take, right? >> right. >> yesterday there was an analysis, or an analogy to sitting on a church bench and you don't bruise your behind. >> that can feel long. >> would it be different if you're sitting on a church bench under -- with a baseball, for example, underneath your butt? >> i really couldn't say. >> all right. >> so in terms of dr. baker's autopsy, you would agree that there's really no objective evidence showing any pressure to the back of mr. floyd? >> there is nothing at the autopsy, that's correct.

>> did you find or did dr. baker find hiypoxic changes in his brain? >> he died too quickly for that to show up. >> and that's when we talk about the lack of ischemic hypoxia, correct, dr. baker noted a lack of ischemic hypoxia. >> i don't remember his exact words. you're describing lack of ischemic changes in the neurons? >> correct, in the brain. >> yes, because that has to happen over a period of time. >> okay. and when someone is experiencing that shortness of oxygen or that lack of oxygen to the brain, that will frequently lead to certain symptoms, right? >> yes. >> confusion is one? >> that could be, yes. >> restlessness?

>> could be, yes. >> shortness of breath? >> could be. >> visual changes? >> could be. >> incoherent speaking? >> could be. >> so to your knowledge did mr. floyd in the videos that you observed ever complain of any visual changes? >> no. >> did he appear to be confused to you? >> so what time -- i guess what time period are we talking about, sorry? >> sure, that helps, maybe if we narrow down that time. the nine minutes, during the nine minutes that mr. floyd was restrained, did he appear confused to you? >> oh, gosh. how do you describe his behavior? >> well, did he -- he was

articulating that he was in pain, right? >> yes. and then he couldn't breathe and he calls for his mother. and he says he loves people. i mean, you might interpret that as confusion or you might interpret it a different way. >> did he appear to be breathing during this time frame? >> not effectively. >> do you know how many breaths per minute? >> no. >> if one expert indicated it was at a rate of 22 breaths per minute, would you disagree? >> i would have no way of assessing that. >> when someone is hypoxic, they start breathing faster, right. >> that can be a mechanism of trying to balance. >> at least for the first five minutes or so mr. floyd was talking.

right? >> well, again -- >> talking, yes or no, he was talking? >> he was -- yes, there was -- there were words, yes. >> so he had on open airway? >> yes. >> and you would agree that -- or would you agree that at some point he went limp. >> yes. >> and would you describe what you saw as the progression of hypoxia in that instance at the point he goes limp? >> that is certainly a good explanation for it, yes. >> was not a sudden high poxic event, right? >> that is my interpretation, yes. >> you would agree that if he was progressively growing hypoxic you would expect whole

body hypoxia? i'll rephrase my question. >> yes, sorry. >> i'm not a doctor so i have to rely on my notes quite a bit. so if he was progressively suffering from whole body hypoxia, the brain would be the first thing that would have -- show signs of hypoxia? >> oh, i see, yes, yes, the brain is the most sensitive. >> and you would agree that that would not occur in a matter of seconds but it would take a matter of minutes, right? >> correct. >> and asphyxia due to position or compression, that prevents air from getting into the lungs, right? >> yes. >> and that leads to what we would call a global hypoxia? >> we haven't really used that word global. >> whole body.

>> i mean, if there's inadequate oxygen the blood flows everywhere. so i guess that's what you're talking about. >> but the brain is the first thing to show symptoms of hypoxia? >> right, that's the most sensitive organ. >> and in this particular case where you have a 90% stenosis of the right coronary artery that's going to be limiting oxygen to the heart. right? >> yes. >> and he has a big heart, right? >> yes. >> needs more blood? >> yes. >> and adrenaline speeds up the heart? >> yes. >> methamphetamine speeds up the heart? >> it can, yes. >> so methamphetamine and

adrenaline cause the heart to work harder? >> yes. >> and increases the heart's oxygen needs? >> yes. >> and at what point does the stenosis in the left and right coronary arteries become critical and cause the heart to stop? generally. >> oh, as a -- are you asking that same question about as a forensic pathologist, what degree of narrowing do we consider potentially fatal? >> right. >> 75% and above. >> now, in terms of drug use, you obviously were aware based on the toxicology that mr. floyd had certain drugs in his system. right? >> yes. >> so when we say on board, that

means in the system? >> yes. >> would you describe the use as you know based on the information that you have as sort of a binge use of drugs? >> oh, i guess i couldn't -- i couldn't answer that. >> are you familiar with drug use taken -- or used interrectally. >> i've heard of that, yes. >> and that increases or speeds up the distribution of controlled substances in a person? >> it speeds up absorption, yes. >> so the effects would be felt much faster? >> yes, they could. >> in a case where you have a person who is experiencing cardiac arrest and they're put

in an ambulance and taken to the hospital for resuscitation, they're often -- there's ivs that are placed in a person. right? >> yes. >> and those ivs contain saline? >> yes. >> and saline can ultimately dilute or decrease to some degree the amount of controlled substances that would be -- as they would be measured? >> that's a theoretical possibility. >> you would agree that fentanyl is a respiratory depressant, right? >> yes. >> it slows breathing and lowers oxygen in the blood? >> yes. >> does the fact that there's norfentanyl in his blood mean that he took it some time ago? >> yes, but by some time, that's -- that's a very vague -- yeah. >> long enough in the past t