tv Day 10 of Trial for Derek Chauvin Accused in Death of George Floyd CSPAN April 9, 2021 10:22am-1:21pm EDT
march 9, march 17, march 21, april 6 and april 7, you would not have any reason to dispute me. >> i have no reason to dispute that. >> you understand notes are made of those meetings and provided to the defense industry? >> i understood that. >> you've also been able to spend a substantial through to time preparing the exhibits that the jury was able to see earlier today? >> correct. >> those are all prepared by you or someone within your team? >> they were prepared by me. >> you provided those to the prosecution in advance of today's testimony? >> correct. >> you understand those provided to me last night? >> i have no idea when but yes. >> all right. you had a lot of time to prepare both yourself as well as the prosecution team in connection with this case, fair to say? >> correct. >> good morning to her honor, counsel, ladies and gentlemen.
the state will call for the first witness doctor lindsey thomas. >> raise your hand. do you swear or af firm under penalty of perjury the testimony you are about to give is the truth and nothing but the truth? >> i do, yes. >> and dr. thomas if you feel comfortable doing so we would ask you to remove your mask. i will keep mine on. >> i would love that come thank you. >> begin by having you state your full name. >> lindsay carol thomas. >> thank you, your honor. good morning, dr. thomas. >> good morning. >> would you please tell us what
kind of a doctor you are? >> i and a forensic pathologist. >> what is a forensic pathologist? >> forensic pathology is that branch of pathology, , which is the branch of medicine where medicine and law overlap. so it could be anything with a medical and legal component, could be toxicology. in some cases it may involve living patients but as i practice and as most forensic pathologists practice it involves what's called medicolegal death investigation. >> does it involve taking care of patients in the clinical sense? >> not living patients, no. a forensic pathologist may be consulted to help with the evaluation and interpretation of injuries in a living patient but not in a treatment or clinical sense. >> most of your work that is the deceased people? >> correct. >> any specific types of death?
>> yes. the state statutes list the types of death that have to be reported to the medical examiner, and briefly they tend to be a natural death, so accident, suicide, homicide. unexpected death, potentially suspicious deaths, that type of category of death. >> do you get special training in how to determine the cause and manner of death in -- >> yes. >> tell us something about the special training you receive. >> well, i start back in medical school or just, just the in part? >> just the end part. >> i did a fellowship in forensic pathology, which is specified training program for doctors who want to be forensic pathologists to learn how to do medical-legal death investigations and manner of death. >> would you tell us what
pathology is of the field of medicine? >> yes. pathologists are sometimes considered the doctors doctor because we don't directly treat patients but we provide information to doctors who didn't do treat patients. so, for example, if you've ever been to a lab and had blood drawn, that goes to a laboratory that is run by pathologist, a clinical pathologist. so blood count, chemistries, things like that. or if you have ever known someone who had a biopsy and was diagnosed with cancer, that's the type of pathology that is done by an anatomic pathologist. so you look at tissue under the microscope and make diagnoses. >> is a medical examiner a forensic pathologist? >> in minnesota a medical examiner is a forensic pathologist who is appointed by the county board of
commissioners to be that counties medical examiner. >> so it's a public official? >> yes. >> so when you talk about the medical-legal investigations, is that sort of the fancy way of describing what you do? >> yes. it's what the medical examiners office does. it's death investigations again when there's a medical component at there may be a legal component. >> is it different from say a death in a hospital? >> yes, yes so if someone din hospital those are usually deaths due to natural causes, and they may have a medical death investigation in the sense that hospital pathologist might get an autopsy, but they wouldn't do the full scope of the medical-legal death investigation because those are mostly due to natural diseases. >> what this death investigation
into? >> welcome the way a medical examiners office performs a a death investigation, i think a lot of people assume it's all about the autopsy, the physical examination of the body. that's really just a tiny part of the death investigation. the death investigation really starts at the very beginning when a death is sound, , a persn is found deceased or the office is notified of the death. we as medical examiners want to know all about that person, what's there past medical history, social, family history. so we will do whatever we need to do to get that kind of history. then we want to know well, what were their terminal in events, what happened around the time of their death. were they complaining that something? was a interacting with someone? with a driving? with it using, you know, machinery, something like that. and then we look at the physical
examination and that part of the exam might include x-rays. it could include gating specimens for toxicology for cultures, for all kinds of other laboratory tests, including looking at things under the microscope, sections of each organ under the microscope. so that's the physical exam part. then we will look at the laboratory results, so that would be usually toxicology but as a say it could be blood cultures or more recently it's probably been a lot of covert testing, that kind of thing. and then look at the microscopic slides, and then put all of that together with the history, the terminal events, the physical findings, laboratory findings and then that's how the medical examiner reaches the conclusion about the cause and manner of death.
>> so all of that goes into death investigation? >> yes. >> you sometimes interview people sometimes? >> yes. the investigators who go to the scene may talk to family members. we certainly will talk to medical providers to get someone's past medical history. we also will interview or talk with law enforcement officers if they were the people who responded. it could be paramedics, ems, troopers, just depends on the case. >> i want to ask you about a phrase used, terminal events. >> yes. >> did you explain to the jury what is a terminal if it? >> sure. when we are investigating a death as medical examiners, as a mention we want to know as much as we can about this person leading up to their death because that often had a little provide us information about how they died. when i talk about terminal event i am talking about what happened
in the three to time around their death shortly leading up to their death. so, for example, he was out shoveling snow, he came in, clutched his chest and fell over. that would be an example of a terminal if it. or windows seven was driving a car and went off the road. that would be what the terminal event was. >> do you also rely on training and expertise i know injuries occur? >> yes. as a forensic pathologist that's one of the things we look at is and learn about is when we see this type of injury we associate that with this type of event. >> what does the medical examiner then due at the conclusion of a a death investigation? >> so the ultimate goal is to complete the information that is needed on the death certificate. specifically the cause and manner of death. >> is a report generated?
>> yes. >> what's the nature of that report? >> one of the main reports that's generated would be considered the autopsy report and that's the report of the physical examination but ultimately the death certificate is kind of the final report. >> now, you told us as a as a forensic pathologist you don't treat living patients. >> right. >> so if we wanted to have a discussion, for example, about measuring lung volumes or air reserves in someone, that wouldn't be your bailiwick as a medical examiner? >> that would not be me, no. by the time i i see them nonef that applies. >> right. so dr. thomas, are you currently employed? >> i work, i'm semi retired. i do consulting and then i work part-time at medical examiners offices in reno, nevada, and
salt lake city, utah. >> reno and salt lake city? >> i really like the way the office runs and i like still to be involved as a medical examiner. >> pretty good places to hike. >> and good places to hike, yes. >> so what -- where did you do you work before you were semi retired? >> right before i retired i was at the hennepin county medical examiners office as an assistant medical examiner. and do you want me to go before that? >> yes, if you could tell us your work experience as a medical examiner forensic pathologist. >> sure. initially i started after my training at the hennepin county medical examiner's office working as a deputy and assistant, then assistant medical examiner, and i was there for many years. and then in 1997 i joined the minnesota regional medical examiner's office that was based
in hastings, and then i was chief of the office for 13 years. and we were the medical examiner's office for eight counties in minnesota, the largest of which were dakota and scott counties. and we also served as an autopsy referral service and medical examiner's office for many other counties in minnesota as well as wisconsin and even one in michigan. and then went out office outgrew that space, dakota and scott counties merged with hennepin county and that's why then i came back to hennepin county. >> so over how many years have you performed work for services as a forensic pathologist? >> let's see, 37 now. 36? >> in minnesota how many county. >> oh, gosh, well i've been a direct medical examiner for eight counties.
i have worked in offices that have been consultant to dozens of other counties. >> and had also perform the services in parts of wisconsin? >> yes. >> when did you start working at the hennepin county medical examiner's office? >> it was early 2017, i retired from hennepin county. >> and how many autopsies would you estimate you have performed over your career? >> probably about 5000 that i myself did, and then hundreds, maybe 1000 more were isis is someone else or i supervised or i persisted in some way. >> so in 5000 or so cases, you will determine the cause or manner of death? >> while actually way more than that. because as medical examiners, we
don't just certify the cause and manner of death for the cases that we do autopsies on. there are numerous other cases that get reported by law to the medical examiner's office where we don't do a physical examination. so, for example, an elderly person falls in a nursing home and gets a hip fracture and then dies a couple months later, that death has to be reported to the medical examiner's office. we will investigate that death by looking at the medical records and doing all what i talked about, giving family input and medical provider input, but we generally will not do a physical examination. but still by law we have to sign the death certificate. >> so you are still determining been the cause manner of death? >> right. we are just not using physical examination part of it. >> using the medical records
primarily? >> yes. >> dr. thomas, are you licensed? >> yes, i yes, i am licensn minnesota, wisconsin, tennessee, nevada and utah. >> do you also hold any board certification? >> yes, i yes, i am board y the american board of pathology in anatomic pathology, clinical pathology and forensic patholog pathology. >> have you worked with any professional organizations over the years related to forensic pathology? >> yes, i have been a member of many different organizations. minnesota medical association, american medical association, college of american pathologists, american academy of forensic scientists and i been on the board of the minnesota coroners and medical examiners association, probably 30 plus years, and then i
remember of the national association of medical s and i was on that board and a member of the executive committee for a number of years. >> and that goes by the acronym name? >> yes. >> what does name do? >> well, there's a professional organization of medical-legal death investigators specifically forensic pathologist, medical examiners. and as an organization they provide support to medical examiners. they provide information. they provide guidelines and accreditation program, an inspection program. lots of ways of assisting medical examiner offices. >> dr. thomas, have you done any teaching? >> yes. i have been a clinical instructor here at the university of minnesota department of pathology. i have done lots of law
enforcement training through the bureau of criminal apprehension here in minnesota, as well as, oh, my gosh, teaching everything from, you know, middle school science students through high school and college and all kinds of professional groups, with its other forensic pathologist come other law enforcement. you know it, you name the organization you come in contact with death investigation and i have probably talked to some of them at some point. >> you have any publication? >> that has it been a main focus of my career but i was, i have several, and early on was involved in an autopsy protocol that was ultimately published by the united nations that is still in use. >> so let's switch topics and talk about your experience testifying in courts.
have you testified before in court? >> yes, probably over 100 times. >> is that predominantly in your role as a medical examiner? >> it's mostly in my role as medical examiner where i did autopsy and in the prosecution would call me to testify as to my findings. i also testified as an expert witness consultant in cases where i didn't do the autopsy but i was called by baby in a civil case either by the defense for the plaintiff -- may be -- if it does a wrongful death or some question about medical malpractice come something like that. and then i have also been consulted anticipating cases at the request of the defense. again not work what i did y over i reviewed some else's work and then i consulted with the defense or testified. >> and have you testified in
minnesota court? >> minnesota, iowa, wisconsin, north dakota, south dakota, pennsylvania. i think those are the ones. >> so dr. thomas, are you being paid for your time and services in this case? >> no. >> could you tell us about that? how does it come about that you are not being paid for your time or services in this case? >> well, i didn't ask to be paid. >> and so did you reach out to the state or did the state reach out to you? >> no, no. you reached out to me. you know, it just, i knew this was going to be important and i felt like i had something to offer and i wanted to do what i could to help explain what i think happened. >> so what were you asked to do
then in this case? >> well, i was asked to review a lot of the materials and come to an independent conclusion about what i thought the cause and manner of death were, and the mechanism for that cause. >> could you give the jurors a general sense or overview of the kinds of materials you reviewed? >> i look at my notes? >> yes, if you need to refresh your recollection. >> so i looked at the hennepin county medical examiner materials, including the autopsy report and toxicology and photographs and microscopic slides, things like that. i looked at the hennepin county medical center records, so mr. floyd's past medical history from their, as well as health partners, medical records. then i looked at a lot of interviews, meaning many videos including body-worn camera
videos, bystander because, surveillance videos, some photographs, still photographs, timelines. and then some medical literature and textbooks. >> so were you the medical examiner who investigated or did the autopsy around the death of george floyd? >> no. that was dr. andrew baker, the hennepin county medical center. >> do you know dr. baker? >> i do. he was a pathology resident when i was on staff at hennepin county many years ago, and then we needed his fellowship i was one of the staff people there. and then after our offices merge i worked again with you at hennepin county. >> so would you have been part of his training in his early formative years? >> yes. >> you consider him a friend? >> i do yes. have you talked to him about this case? >> no, , not since right after t
happened. >> at you did review his report? >> yes. >> as well as mr. floyd's medical record? >> yes. >> did you review the history of terminal events on may 25, 2020? >> yes. >> so -- >> what was kind of unique of what was absolutely unique in this case was the volume of materials i had to review. i have never had a case like this that had such thorough documentation of the terminal events. >> and by what of the thorough documentation, what makes it so thorough, in your opinion? >> well, the use of videos is unique in this case your certainly as medical examiners we use videos but there's never been a case that i've been involved with that had videos over such a long time frame and from so many different perspectives. >> are you aware that of
dr. baker's conclusions than on the manner of death? >> yes. >> your honor, i would like to show exhibit 193 that is been stipulated subject to dr. baker's foundation. so first, dr. thomas, what do we see on exhibit 193? >> this is a copy of the certificate of death of mr. floyd. >> okay. and so if we could highlight just through the word underlie. just to make it a little bigger. based on your review of the evidence and the death certificate, do you agree with dr. baker's determination on the cause of death? >> yes, i do. >> and is that by the word
immediate on your? >> yes, cardiopulmonary arrest some dual restraint and neck compression. >> have you, dr. thomas can form an opinion about the mechanism of death? >> yes. >> would you tell us what that is? >> in this case i believe the primary mechanism of death is asphyxia or low oxygen. >> so we will come back to the mechanism in just a minute. can you explain to the jury what this cause of death means and why you agree with it? >> well, it's kind of in two parts. there's a cardiopulmonary arrest which doesn't provide a lot of additional clarifying information because in the way everyone dies, when your heart stops and your lungs stop, that's cardiopulmonary arrest. but as a forensic pathologist i would use cardiopulmonary arrest
when -- to differentiate it from a cardiac arrest. so this is not a sudden cardiac death, a sudden cardiac arrhythmia. this is a death were both the heart and lungs stopped working. and the point is that it is due to law enforcement some dual over restraint and compression. that is kind of what ultimately is the immediate cause of death is the some dual restraint and -- >> just so it is clear for the jurors, cardiopulmonary arrest means heart attack? >> no. >> does it mean fatal arrhythmia as a primary cause of death? >> no. >> itself a means heart stops and the lungs have stopped? >> correct. >> another way simply describing death itself? >> correct. >> can you explain what's referred to looking here at the terms some dual restraint and
neck compression? >> those were activities by the law enforcement agency officers involved. some dual is subduing someone, trying to restrain them is in mr. floyd's case, involved handcuffing him, his positioning on the ground, the prone position, people kneeling on him and neck compression is than the on the neck specifically. additionally there was some back and other things being compressed by the officers. >> so if you put all this together, cardiopulmonary arrest, complicating law-enforcement subdual, restraint and neck compression, what does that mean? >> well, what it means to me is that the activities of the law
enforcement officers resulted in mr. floyd's death, and specifically those activities where the subdual, the restraint and the neck compression. >> and this is also represent your own conclusion? >> yes. >> a conclusion you have reached and the opinion you hold to a reasonable degree of medical certainty? >> yes. >> would you tell us what you reviewed in order to reach this conclusion? >> all of those things that he mentioned earlier, the -- again, what a sort of unique about this case is that often i would just review the medical examiner case file and that would provide information about what the cause and the manner of death is. but in this case the autopsy itself didn't tell me the cause and the manner of death. and it really required getting all of this other additional information, specifically the video evidence of the terminal
events, to conclude the cost of death in the manner of death. >> when you made reference to something called a mechanism of death, would you tell us what mechanism of death means? >> so cause of death is what's the thing, the disease or the injury or the process that caused someone's death. but the mechanism is what was going on in the body at that time. so, for example, the cause of death might be a gunshot wound. but the mechanism of death might be blood loss related to the gunshot wound, or you know, an infection that complicated that gunshot wound down the road come something like that. so it's more of what was actually happening at the body level that resulted in the cause of death. >> so focusing in on the mechanism of death here, how is
it that the officers subdual restraint and neck compression cause mr. floyd's death? >> so as i i mentioned i thine primary mechanism was asphyxia or low oxygen, and it basically is mr. floyd was in a position because of the subdual restraint and compression where he was unable to get enough oxygen in to maintain his body functions. >> what's required for normal briefing, dr. thomas? >> what is required? well, i kind of three components. you have to be able to get air in, so you have to have what is called a patent airway and that could be nose, mouth, you know, soft tissues of the neck, the trachea, the larynx, x, trachea, bronchi, all that has to be open. at the level of the lungs itself there has to be adequate air
exchange between oxygen coming in, carbon dioxide going out. and then finally the way of lungs work is it's kind of like bellows, that when you suck in error your diaphragm drops in pulse here in and when you relax the diaphragm collapses and pushes air out. so all three of those things has to be functioning in order to get adequate oxygen in. so, for example, if someone is smothered or strangled or they inhale a piece of hot dog or the have pneumonia such that the lungs are completely filled, then their airway is obstructed so that there is an adequate air coming in, oxygen coming in. or if someone is in an environment where there isn't enough oxygen, so, for example,
in a closed garage in which an old car has been running, there may be way high carbon monoxide. and in that case they are perfectly able to breathe in and out that there just isn't enough oxygen. and then the third would be if there some kind of restriction such that your chest can't expand, your diaphragm can't expand so the bellows function is a working. and if anyone of those components isn't working, then the result will be this mechanism of an adequate oxygen. >> doctor, how does narrowing of the hypopharynx fit into the? >> well, the example i would give that people are probably most familiar with his sleep apnea or snoring. if you yourself or have a partner who snores you know that especially in certain positions, what happens is the hypopharynx, which is sort of the soft tissues at the back of your
throat, will kind of collapse because there's inadequate air coming either forcing it out or forcing get in which his wife a cpac machine works is because it forces air through that sloppy area. and if that collapses, then it makes it difficult to get air in. >> so dr. thomas, what you rely on to reach the conclusion that low will oxygen was a mechanism of death? >> in this case it was primarily the evidence from the terminal events, video evidence, that show is the stiffly in a posn where he was unable to adequately briefed. >> so how does the autopsy report itself assist you or not? >> so the way the autopsy really helps is it's great for ruling things out. so in this case the autopsy
ruled out, for example, underlying lung disease. mr. floyd had had a history of covid, but there was evidence in his lungs at the time of his death that he had any lung disease that would impair his ability to breathe. and it ruled out injuries to the neck that suggest that his, the bones in his neck had been broken, for example. and it ruled out a stroke. he didn't have a stroke so wasn't like his blood pressure was so high that eruption of vessel in his brain. he didn't have any aneurysm. he didn't have, which is a ruptured vessel. he didn't have a listen which is a a blood clot. he didn't rupture his heart. he didn't have an old heart attack or recent heart attack, or what is called myocardial infarct. so the autopsy is really great for ruling things out.
>> dr. thomas, just to focus on one of those, you said the autopsy ruled out a recent myocardial infarction? >> yes. >> how does it do that? >> well,, win a forensic pathologist examines a heart, one of the things a look at is the coronary arteries which are the vessels that supply blood and nutrients to the heart muscle. and then the pathologist will examine a muscle of the heart. and if someone has had a recent heart attack, there may be evidence in the heart muscle of that damage. or if they've had a prior, an older heart attack there will be scarring in the heart muscle that shows that area of damage. >> thank you, doctor. is it normal as a part of your death investigation then to seek out and to look at the videos? >> yes.
oh, yes. >> in this case is there any particular video footage that strike you as more significant than others from what you saw? >> oh, gosh, this case there were so many. the body-worn camera videos were very instructive because they started -- well, and the cup foods video because they showed how mr. floyd was behaving long before law enforcement interactions. then the body-worn cameras show the early interactions before there was any of this subdual restraint and compression. then they show the interactions during the subdual restraint. the bystander videos i really instructive as well as the surveillance videos from the scene at, shelling kind of
during the time of the restraint. so there were lots -- showing. >> in terms of the video footage then either ruling in a cause for ruling out a cause, how did it inform your assessments about the cause of death? >> well, it helped me rule in a cause and also rule out causes, i would say. >> so did it help you determine whether this was what i might refer to as a lights out kind of death, a sudden death? >> right. so what i observed from all of these videos is this is not a sudden death. mr. floyd did not -- it's not like the snow shall the right told you somebody comes in, collapses and clutches their chest and falls over. there was nothing sudden about his death. so that's what i would've expected if it was a cardiac arrhythmia or abnormal beating of the heart.
typically those are someone really falls over pretty quickly. and this was not that. likewise, it was not the type of death that has been reported in fentanyl overdose, for example, where someone becomes very sleepy and then just sort of gradually, calmly, peacefully stops breathing. this was not that kind of a death. so i felt comfortable ruling out those as causes of death. and then on the flipside, i could clearly see from watching the video what happens to mr. floyd during this subdual restraint and compression and what happens to his breathing is, it gradually becomes more difficult and then stops. >> doctor, tell us what is the bellows function?
>> well, what your diaphragm does along with the muscles in between your ribs. so when you taking a deep breath, what's happening is your rib cage is expanding, and that then forces the lungs to open up and that's what draws air in. so when someone is intubated in like surgery or something, it sort of the opposite of that because your diaphragm is paralyzed and so somebody has to force air in, but under normal breathing circumstances you just -- it's the bellows, it's the polling error in. .. behind his back his hands were
tucked, so that is a difficult position to be in, very prone and handcuffed. and then with, at times, at least three officers on top of him, whether it is his neck or back or his lower back or legs, it prevents them from moving his body into a position where he can adequately use his belleau function, and his chest is, compressed in this position, in such a way that he cannot adequately stand and get enough oxygen. >> over what period of time with this? >> nine minutes. >> what did you see in those minutes that led you that led to the mechanism of death was low
oxygen? >> well, initially, mr. floyd was able to struggle pretty vigorously when he was in this position when he recognizes it's going to be hard for him to breathe. >> that's the last part of the question as speculated about mr. >> so initially when he is in the prone position he is breathing and speaking and i might look like a oh, at that point he is getting enough air exchange. but over time, you can see that his breathing is getting more and more difficult and he is saying less and less about halfway through the whole restraint and dual compression
process and the he is speaking but not entirely and then shortly after that there is a movement that i believe what is a brain reaction which kind of looks like a twitch and it is something that the body does when the brain is no longer has enough oxygen. that is the point at which you can tell by looking, oh, that is where he is no longer getting enough oxygen to his brain. and then the restraint continues for many minutes more, even after someone says hey, there is no polls, they maintain the position. so at that point his heart has
also stopped in his breathing has stopped and his heart has stopped. >> so you mentioned the brain reaction, is also known as anoxic seizure. >> yes. >> is that something someone does consciously and voluntarily >> no, it is something that your body does on your brain doesn't have enough oxygen. and that's why when someone witnesses when they die they say oh, they had a seizure and died. but they basically die because they have a muscle twitch after losing wind in their system and oxygen that looks like a muscle twitch. >> exhibit 193, going back to that now in front of you, the other contributing conditions if we can talk about that, please.
do you see where i am referring to the other contributing conditions? >> yet. >> what are those? >> in this case hypertensive heart disease, recent methamphetamine use and fentanyl intoxication. >> can you explain to the jury what does it mean about other intoxicating conditions? >> the way that forensic examiners usually view this is that people often think that death certificate is for that person, that specific person that died as well as their family, and that is true, it does serve a useful purpose for life insurance and whatever. okay, but forensic apologists are also using these death certificates for public health data for business. so in any given case, we are not
just thinking about this particular person and you're also thinking that the state in government collects data on why people die and in the cause of death. it is how we know as a country how many people die of covid-19, it is because the death certificate lists that. so one of the things we use this for is to list the disease process or drugs that are present at the time of death, but that we don't directly -- that we don't directly continued in turn contribute to the cause of death, so that someone looking at data years from now can say okay, we would like to do and the valuation of all deaths during law enforcement in
this way. so how much also involves someone who had drugs? because that could be something that is relevant and trying to prevent her death in the future. or the case where i use other conditions the most is the hip fracture case that i talked about, where someone dies of a hip fracture due to a fall, but they are 84 years old and may also have hypertensive heart disease, a atherosclerosis, asthma and diabetes. so i would list those as other contributing conditions. in no way do those things cause a fall and the resulting letting go and pneumonia. but from a data perspective, someone might want to know of the 84-year-old women that die of hip fractures, what percentage have underlying heart
disease, because again, from a data collection standpoint, does that provide useful public health information that can be used to prevent theft? so that is how i would use this. >> very long-winded, i'm sorry. >> no, that is okay, doctor thomas. so other contributing conditions , but they are not the direct cause. >> exactly. >> did you consider these other assessments of the cause and mechanism of death to avoid? >> yes. >> how did you consider that? >> welcome i wanted to look at each one as a question, is this the cause of his death, he has narrowing of the coronary arteries. in many cases that is the cause of somebody's got.
so i looked at that and again, it comes down to what where the history of determined event, does this look like the type of death that we see, as a forensic pathologist i know from family describing what happened at the time of death, that this does not fit what has been described from someone who dies of cardiac arrhythmia of arthur were set of cardiac death, cardiac arrhythmias, which was not that kind of debt. >> so again i don't treat patients, but what i know from family members who described death that later turn out to be due to fentanyl, well, it is
peaceful, they fall asleep, they could hear snoring were deep reading and there is no struggle. they oftentimes were slumped over because they were very slow in death. so totally different then what is seen in the death of mr. floyd. methamphetamines, generally, it is again something that could cause a cardiac arrhythmia, a seizure, by that i don't just mean terminal or not is a twitch, but the full-blown seizure, again, looking from what i know because it is so well documented, it does not fit with the methamphetamine. >> so you reviewed toxicology?
>> yes. >> so how would you characterize the amount in his system? >> well, it was there, it is not particularly high. certainly in death that i have attributed to methamphetamine use and has been much higher, but it's not like there's any space left, but this is a very low level. >> so was it significant in the cause of death in your findings? >> no. >> vase upon your review of the video and the application of work experience and knowledge, rule out drug overdose as a cause of death? >> yes. >> and that is a opinion do you hold to a reasonable degree of medical certainty? >> yes, it is. >> does the medical examiner
also complete the death certificate? >> yes, we do not issue it, it comes from county or state. but as the medical examiner we fill out all of this and how it occurred and all of this. >> how many death certificates have you filled out? >> oh, goodness, well, thousands and thousands. >> okay, if we will care at the exhibit in front of you, 193, in the left margin, we see the reference to underline. can you tell the jurors what that means? >> yes, let's go back to the hip fracture, i keep referring to that, but for example, someone that dies of a hip fracture, what happens is someone gets a fracture, they get it surgically repaired, they may get pneumonia or something like that. and so in that kind of case we would look at the immediate cause of death as pneumonia.
the underlying cause is the hip fracture, and the underlying cause of the hip fracture was the fall. so they got a hip fracture and then they got pneumonia. and so it is something that is used when you have a death that has maybe multiple sequences of events. but in a case like this you don't need underlying because it's all included in the first line. it is all due to the law enforcement restraint and the compression that was used. >> the death certificate does not is the word is 60 a, would you have used the word asphyxia in this case? >> probably not. i cannot use it very often because it requires a lot of explanation and it doesn't really offer much additional
information unless you have a chance to have a discussion about what it means. so i tend to just list -- if someone dies of hanging, that's a type of asphyxia, but i would not say expects the outcome i would say hanging. >> so to refer to asphyxia or low oxygen, it doesn't tell you why it was asphyxia. >> correct. >> the findings suggest low oxygen as the cause of death? >> no, there was nothing that shows low oxygen. >> there are no test that could be done? >> no, no. >> are there physical findings that sometimes may be found and could be consistent with low oxygen? >> so there are no physical
findings that show low oxygen, but there could be physical findings that show consistent with a cause of death that could result in low oxygen. for example the hanging. and if someone is partially hanged, partially suspended, there is only some pressure on her neck, they may have what is called pinpoint hemorrhages because blood is going into the head but not able to drain due to the pressure on the neck. so at the autopsy we will see the the finding is consistent with hanging, which is a mechanism or hanging is the type of asphyxia.
or in manual strangulation. we could see some bruising or we might see broken bones in the neck. the mechanism of death and strangulation is low oxygen but the findings that we are seeing is consistent with strangulation. so it is a fine line, it is in the low oxygen that we see, but sometimes, not always, sometimes we see in cases where it's the result of low oxygen, we see specific findings related to the cause. >> so if you then see the condition of petechaie.
>> yes, that is correct, when it's broken bones or bruising, it's very hurtful and putting together a picture of what might happen, but if you don't have them, it doesn't help you one way or the other. >> by that one way or the other it means that you cannot conclude from that alone that person did or did not die a low oxygen. >> exactly. >> and you mentioned losing in that context? >> yes, sometimes for example, strangulation. sometimes we have all kinds of bruises that you can see on the head and neck. other times there is a strangulation case and they don't have a single mark. and so there is all kinds of reasons where if it's there, it's very helpful and if it's not, it's not helpful. >> findings of the death investigation that were findings
on the cause of the death of george floyd? can you tell us what those are? >> mr. floyd had superficial injuries, specifically on his face, on his shoulders and what that does is it supports what i saw in the videos, which he is being forcibly restrained and subdued and he is trying to move into a position by rubbing his face against the concrete cement of the ground, and by pulling against his handcuffs, you can see the injury to the rest is on the handcuffs, and by pushing with his shoulder. he also had scrapes on his knuckles on his right hand and that was from him pushing to try to get into a position where he could breathe.
>> doctor thompson, other photographs that depict what you're talking about? >> yes. >> we have individual packets for the jurors to view this. >> there is some stipulation that we are going to be showing you, or as we call, published to you. we are not going to put everything on the monitors, we are not going to broadcast it, but everyone in the courtroom will have access to this including themselves, especially a packet. and the actual exhibit will be available in deliberation. >> the deputy or someone, would they like to speak on this?
>> she can have mine. >> that way they won't have to use the camera at all. >> so doctor thomas, if we start with the exhibit that is marked 185. >> yes. >> i take that back, doctor thomas, looking at the exhibit 185, what is the difference in this photograph that informs your conclusions pertaining to this as a cause of the death of mr. floyd? >> this is a photograph of mr. floyd space, and it shows some facial injuries, most
notably what i call abrasions, which are scrapes, over his left eyebrow and over his left cheek, you can also see that there are little or scrapes or small cuts on his nose and his upper lip and a little bit on the left side as well, but the main thing that it shows is that the left side of his face was obviously in contact some rough surface. >> looking at exhibit 235, there could be a close-up of the same area. >> here we go, yes, yes. that is a close-up of the left
cheek and the left for head and you can see, for example, above the left eyebrow, there is a dark area that is a dried scrape, as well as there is a little bit of discoloration of skin as well so that there is also a bruise there. and then on his left cheek you can see the darker area as well as a lighter orange pink area, and those are against scrapes, the dark area is where a scrape has tried. >> what does that tell you about the cause of mechanism of his death? >> it is consistent with the impression of watching the video that his face was on the ground and that he was moving his face and effort to get into a position.
>> let's look at exhibit 188. >> this is a photograph of mr. floyd left shoulder. >> what is this. >> this is an area of scrapes, indicating that there is force between his shoulders and rough surface and in this case the ground. again, it is consistent with what is on the video that he is struggling to push himself into a position where he can breathe. >> looking at exhibit 187. >> this is a photograph of his shoulder and you can see there is a little bit of discoloration
and the skin is scraped. so there is less injury impact here which sits with what you see in the video and which had more contact. >> to look at exhibit 189. >> this is a photograph of his left hand. so if you look at the hand over his wrist, you can see there are areas of red, kind of a pale area in between and that was marked and you can also see on the outer edge there is white material that is dried skin,
that is an area where his skin has actually been roughed up. >> doctor, exhibit 190? >> on exhibit 190, this is a photograph of his right hand and wrist and again, in this case you can see more clearly the double lines and discoloration above his right wrist that is assistant with the handcuffed marks and it indicates pressure against the handcuffs and again on the outer edge you can see there is a little bit where it is darker. that is an area where the skin has been scraped. also on this photograph, you can see the knuckles of his index
finger and his middle finger, there are skin that are scraped off and as you can see with the video where he is pushing against the rim of the car tire or something, to try to push his body into a position again where he can breathe. >> thank you, doctor thomas. if you could put the photos away, please, for five-minute period. >> if you could, please.
>> is so doctor thomas has not looked at this physical evidence from the autopsy, what is the evidence enough by itself conclusive? >> know, there are multiple ways that scrapes and bruises can happen. >> it's only useful in the context of what is seen in the videos. >> was there any evidence to suggest that mr. floyd was suffering from a potentially fatal condition on the evening of may 25, 2020? >> no.
>> do you have an opinion to a degree of medical certainty that if he would not have been passed away that night, that he would not have been subject to the constraint? >> there is no evidence to suggest that he would've died that night except for the interactions with law enforcement. >> were there other mechanisms that you felt contributed to his death? >> yes. >> could you generally characterize what those were? >> yes, i think a secondary mechanism is whatever word to as physiologic stress. by that, i do not mean the stress that someone is a type a personality and they are stressed about it. not that kind of stuff. i'm talking about the physical stress that you feel when you
drive along and i'll look on son in a car swerved in front of you. .. .. i see my toddler and that just, the rush of adrenaline you get and you feel lost and you get goosebumps and your heart races and you feel short of breath and then there they are, they're getting an ice creamcone . you say okay, but it takes you a minute for your heart the kind of slow down your
blood pressure to slow down and for you to be able to take a deep breath andrecover yourself . that is the kind of stress i'm talking about yet instead of that only a second or minute this goes on for minute after minute after minute for nine minutes where you are terrified and you can't, there's no recovery. so it's that kind of fear of life that i'm talking about for physiological stress >> are you able to tell us what is going on in the body during the physiological stress ? >> it's the reactions are you get chemical release. you get adrenaline or epinephrine and those are things thatmake your heart rate, your blood pressure go up . you require more, your muscles get ready to act. they will run to do whatever you need to do, slam on the brakes so you start needing
more oxygen in your muscles. you need totake more brats . you need more oxygen for your heart rate because your heart is beating faster. there may be other chemicals that are released whether it's stress hormones or cortisolor things like that . there may be lactic acid that's produced as your muscles, you know when you have a heavy workout. your muscles are tired and kind of sore. it's because there's been an increase in lactic acid and it's your muscles working so all those physical things, those chemical things can cause reactions in the body that put additional stress primarily on your heart but also on all of your body symptoms because your body requires your chemistry to be
in very fine balance. and when there's too much say lactic acid or not enough, not an ability to compensate for that elevated lactic acid , then all your body organs will get into trouble. >> doctor, do you consider that physiological stress as you described it a direct cause or mechanism of death or is it secondary? >> i guess i would just consider it a contributory cause or contributory to the cause of death . it's another contributing mechanism. >> so the direct cause is blood and the secondarycauses what ? >> the primary is asphyxia and the secondary is low oxygen and secondary is just
physiologic stress but ultimately the cause of death is the dual restraint and compression. >> so this physiologic stress or physiological stress that we are discussing, is that something that could be observed on autopsy? >> no. >> why is that? >> it's a chemical reaction. it's increased heart rate which we don't see, it's increased chemicals that we can't test for atautopsy . so none of it is anything that nbc men physically. >> so it's a functional mechanism. >> yes, that's a good way of describing it. >> is low oxygen also a functional mechanism ? >> yes.
so could you tell us how you felt that the physiological stress was significant to your conclusion on the cause of mister floyd's death. >> mister floyd was already in a position where he was experiencing difficulty breathing and getting enough oxygen in his body. and on top of that now there is this physiological stress putting increased demand on his heart, increased demand on his lungs, increaseddemand on his muscles . so all the things he's using . his muscles, his strength, his body to try and get himself into a safe position where you can breathe. those are doubly stressed by the position that he's in as well as the underlying chemical reactions going on
in his body so it's sort of a double whammy to his heart and lungs and musclesin his whole system . >> doctor thomas, i want to show you exhibit 194. this is stipulating the foundation. first, doctor thomas, can you tell us what this is? >> this is a press release put out by the hennepin county medical examiner's office at the time they certified the cause and manner of death of mister floyd. >> and is it your understanding the medical examiner's office generates this type of a press release report in certaincases ? >> yes. >> so there's a section in the press release report that
refers to a matter of death . >> yes. >> and we see the word their homicide. >> yes. >> we see also in here, on the death certificate when the press release says also how the injury occurred. >> yes. >> would you read that for the record. >> subject experienced cardiopulmonary arrest while being restrained by law enforcement officers . >> doyou agree with that ? >> yes. >> let me show you what was marked as exhibit918 . and homicide is a matter of death. >> yes. >> would you explain to the jurors a little bit about what it is medical examiner's look towhen they're trying to determine manner of death . >> certainly. unlike cause of death which
could be anything, weonly have five options for medical . a death can be natural, meaning all the conditions that just in a process,. category accident that would be something like a motor vehicle crash or unintended drug overdose. category is suicide, was on hand and probably some element of it. the fourth category side that means death of another. the fifth category is undetermined. that means generally, we don't have enough information about this type of death to make a determination to fit is one of the other categories. so for several we talk a lot
about terminal events early on in some cases we have no idea what theterminal events are . we don't know because they've been alienated from family, we don't know what they were saying. they, do they have a prolonged history of using drugs? did they get out of prison? we're unable to get information to sort it into it it's an accidental death or an intentional suicide. that would be an example where we might use undetermined don't have enough information. >> if you look at the screen in front of you, does this depict or showthe manner of death ? and homicide is highlighted reflecting what doctor baker saw red and do you agree with that finding in the case of george floyd? your honor, we offer exhibit 918.
>> exhibit is highlighted, is that correct ? >> yes your honor. yes. >> 918 is received. >> for the ladies and gentlemen of the jury these are the five matters of death you were describing doctor thomas? and we highlighted homicide to reflect what doctor baker found and that you agree with . >> yes. >> is there any guidance given to medical examiners
about how to select homicide as a matter of death? >> yes. there is a guide that was published by the national association of medical examiners that provides assistance in how to make a determination between these different types. >> i want to show you what's been marked as exhibit 952. >> you see that doctor thomas ? and is this publicationthat provides guidance to medical examiners on how to determine manner of death ? >> yes. >> would experts on this diet be valuable to your testimony >> we offer excerpts from exhibit 952 . >> i do object to this your honor. >> actually, we can deal with these issues.
we will take our 20 minute, we're probably going to have to come back around five after. 11:05. >> today on this 10th day of the trial of derek chauvin charged in the death of george floyd may 25, 2020 the end of the second week of trial as they continue with testimony of doctor lindsay thomas, biologist and a reminder we will re-air tonight's testimony beginning at 8:00 tonight on c-span2 and all the coverage of the past available at c-span.org. we expect them to return in
about 1205 eastern, 20 minutes or so and until then, of the testimony from earlier from doctor thomas . >> good morning your honor, counsel, ladies and gentlemen. the state will call their first witness, doctor lindsay thomas. >> do you swear or affirm under penalty of perjury the testimony are about to give will be the truth, whole truth and nothing but the truth . >> i do.
>> doctor thomas, if you can remove your mask i willkeep mine on. and begin by having you state your full name, each of your names . >> lindsay carol thomas. >> ms. blackwell. >> thankyou your honor . >> morning doctor thomas. would you tell us whatkind of doctor you are ? >> i am a forensic apologist. >> what is a forensic apologist. >> forensic ecology is that branch of ecology is a branch of medicine where medicine and law overlap. so it could be anything g with our medical and legal component, could be toxicology, in some cases it may involve living patients but as i practice it is most runs six biology experts practice it involves medical legal investigation. >> does it involved taking care of patients in the clinical sense ?
>> not living patients. a forensic apologist may be consulted to help with the evaluation of injuries and a living patients but not in the treatment. >> so most of your work is done, any specific types of deaths? >> the state statutes list types of deaths that have to be reported to the medical examiner and briefly, they tend to be unnatural deaths so accidents, suicide, om homicide, unexpected death. potentially suspicious deaths. at typeof category of death . >> you get special trainingon how to determine the cause and of death ? >> yes. >> tell us something about the special training you receive . >> should i start back in medical school for just the end part ? >> just the end part. >> i did fellowship in
forensic pop is a testified training program for those who want to be forensic apologist to learn how to do medical legal death investigations and cause and manner of death. >> would you tell us what biology is? >> biologists are sometimes considered the doctor's doctor because we don't directly treat patients but we provide information to doctors who then do treat patients so for example, if you've ever been to allow and had blood drawn, that goes laboratory that is run back apologist, a clinical apologist so what account, chemistries, things like that or if you've ever known someone at half biopsy was diagnosed with cancer, that's the type of ecology that is done by an anatomic
pathologist so you look at tissue under the microscope. >> is a medical examiner a forensic apologist ? >> in minnesota a medical examiner is a forensic apologist is appointed by the county board of commissioners to be counties medical examiner. >> so it's a public official. >> yes. >> when you talk about the medical legal investigation, is that sort of a fancy wayof describing what forensic apologist to ? >> yes, it's what the medical examiner's office does is death investigations again where there is a medical component and there may be a legal component. >> is it different from say i death at a hospital. >> yes, so if someone dies in a hospital, those are usually deaths due to natural causes and they may have a death
investigation in the sense that a hospital apologist might do an autopsy but they wouldn't do the full scope of the medical legal death investigation because are mostly due to natural diseases. >> what does death investigation entail? >> the way a medical examiner's office performs a death investigation, i think a lot of people assume it's all about the autopsy, the physical examination of the body. and that's really just a tiny part of the death investigation. the death investigation really starts at the very beginning when a death is found, a person is found deceased or the office is notified of the death. we as medical examiners want to know all about that person . what's their past medical history, social history, family history so we will do whatever we need to do to get that kind of history. and we want to know well, what were their terminal
events, what happened around the time of their death. really complaining of something, were they interacting with someone? were they using machinery, things like that and we will look at the physical examination and that part of the exam might include x-rays , it could include getting specimens for toxicology or cultures or all kinds of other laboratory tests. including looking at things under the microscope, sections of each organ under the microscope. so that the physical exam. then we will look at the laboratory results . that would be usually toxicology as i say it could be blood cultures or more recently it's probably been a lot of covid testing and put
all that together with the terminal events, the laboratory findings, and that's how the medical examiner reaches a conclusion about the cause and manner of death. >> sometimes do you interview people as you approach ? >> the investigators who go to the scene they talk to family members. we certainly will talk to medical providers. to get some someone past medical history and we often will interview or talk with law enforcement officers if they were the people who responded. it could be paramedics, ems troopers, it just depends on the case. >> i want to ask you about the phrase you use, terminal event. could you explain to the jury what is aterminal event ? >> so when we are investigating a death as
medical examiners, as i mentioned we want to know as much as we can about this person. leading up to their death because that often is how they lived will provide us information about how they died. when i'm talking about terminal events, i'm talking about what happened in the period of time around their death, leaving shortly up to their death. so for example he wasout shoveling snow , he came in and clutched his chest and fell over that would be an example of a terminal event or we know someone was driving a car and went off the road. that would be what the terminal events were. >> you also rely on training and expertise on how injuries occur? >> yes, as a forensic apologist as one of the things we look at his and learn about is when we see this type of injury, we associate that with this type of event.
>> went to the medical examiner then do at the conclusion of a death investigation ? >> the ultimate goal is to complete the information needed on the death certificate . specifically the cause and manner of death . >> is a report generated western mark. >> yes. >> what's the nature ofthat report ? >> one of the main reports would be considered the autopsy report and that's the report of the physical examination but ultimately the death certificate is the finalreport . >> you told us as a pathologist you don't treat patients. so if we wanted to have a discussion for example about measuring one file or reserves in someone, that would be your bailiwick. >> would not be me. >> by the time i see them, none of that applies.
>> so doctor thomas, are you currently employed? >> i'm kind of semiretired. i do consulting and then i worked part-time at medical examiner's office is in reno nevada and salt lake city utah. >> reno and salt lake city. >> i like the way the office runs and i like still to be involved as a medical examiner. >> pretty good places to hide . >> good places to hide, yes. >> where did you your work before you were semiretired ? >> right before i retired i was at the hennepin county medical examiner's office as an assistant medical examiner. and do you want me to go before that? >> could you tell us your work experienceas a medical examiner and forensic apologist ?
>> initially i started after my training at the hennepin county medical examiner's office working as a deputy and assistant and assistant medical examiner and i was there for many years and then in 1997 , i joined the minnesota regional examiner's office was based in hastings and then i was chief of that office for 13 years and we were the medical examiner's office for eight counties in minnesota. the largest of which were dakota and scott county . we also served as an autopsy referral service and medical examiner's office for many other counties in minnesota as well as johnson and even one in michigan. and then, when what our office outgrew that space, dakota and scott county merged with hennepin county and that's when i cameback . >> over how many years have
you performed the services as a pallet just? >> 37 now. >> how many counties? >> oh gosh. i've been a direct medical examiner for eight counties. i worked in offices that have been consultant to dozens of other counties. >> and have you also performed those services as part of the county? >> yes. >> when did you stop working at the hennepincounty medical examiner's office ? >> it was early 2017 when i retired from hennepin county. >> how many autopsies would you estimate were performed over your career? >> probably about 5000. i myself did and hundreds,
maybe thousands more where i assisted someone else or i supervised or i participated in some way. >> so in 5000 or so cases, you've determined the cause and manner of death. >> actually, way more than that. because as medical examiner's , we don't just certify the cause and manner of death for the cases that we do. there are numerous other cases that get reported by law to the medical examiner's office where we don't do a physical examination. so for example, an elderly person falls in a nursing home and get a hip fracture and then dies a couple months later. death has to be reported to the medical examiner's office . we will investigate that death by looking at the medical records and doing all of what i talked about. getting family input and medical provider input. but we generally will not do a physical examination, but
still by law we have to find the death certificate. >> so you're still determining the cause and manner of death. >> right, we're just not doing and a physical examination is part of it . >> doctor thomas, are you licensed? >> yes, i'm licensed in minnesota, wisconsin, tennessee, nevada and utah . >> do you also hold any board certifications? >> i am board certified by the association of pathology and anatomic apology, clinical pathology and forensic anthology. >> had you worked with any professional organizations over the years related to forensic anthology ? >> yes, i've than on a number of different organizations, the american medical association, college of
american pathologists and american academy of forensic scientists and then i'm on the board of the minnesota coroners medical examiner's association. probably 30+ years. and then i'm a member of the national association of medical examiners and i was on that board and a member of their executive committee for a number of years. >> that goes by the acronym main. what does maine do. >> they are the professional organization of medical legal death investigators, physically forensic pathologist and medical examiners and as an organization they provide support to medical examiners. they provide information. they provide guidelines and accreditation programs and inspection programs, lots of ways of assisting medical
examiner offices. >> doctor thomas, have you done any teaching western mark. >> yes. i have been a clinical instructor here at the university of minnesota department ofpathology . i've done lots of law enforcement training through the bureau of criminal apprehension here in minnesota. as well as all my gosh, teaching. everything from middle school science students through high school and college and all kinds of professional groups whether it's other forensic apologist or law enforcement. >> ..
>> so let's switch topics and talk about your experience testifying in courts. have you testified before in court? >> yes, probably over 100 times. >> is that predominantly in your role as a medical examiner? >> it's mostly in my role as a medical examiner where i did autopsy and then the prosecution would call me to testify as to my findings. i also testified as an expert witness consultant in cases where i didn't do the autopsy but i was called by maybe in a civil case either by the defense
for the plaintiff if it does a wrongful death or some question about medical malpractice, something like that. and then i have also been consulted anticipating cases at the request of the defense. again not what i did autopsy over i reviewed some else's work and then i consulted with the defense or testified. >> and have you testified in minnesota court? >> minnesota, iowa, wisconsin, north dakota, south dakota, pennsylvania. i think those are the ones. >> so dr. thomas, are you being paid for your time and services in this case? >> no. >> could you tell us about that? how does it come about that you are not being paid for your time or services in this case? >> well, i didn't ask to be paid. >> and so did you reach out to the state or did the state reach out to you? >> no, no. you reached out to me. you know, it just, i knew this
was going to be important and i felt like i had something to offer and i wanted to do what i could to help explain what i think happened. >> so what were you asked to do then in this case? >> well, i was asked to review a lot of the materials and come to an independent conclusion about what i thought the cause and manner of death were, and the mechanism for that cause. >> could you give the jurors a general sense or overview of the kinds of materials you reviewed? >> may i look at my notes? >> yes, if you need to refresh your recollection. >> so i looked at the hennepin county medical examiner materials, including the autopsy report and toxicology and photographs and microscopic slides, things like that. i looked at the hennepin county medical center records, so mr. floyd's past medical history
from there, as well as health partners, medical records. then i looked at a lot of interviews, many, many videos including body-worn camera videos, bystander videos, surveillance videos, some photographs, still photographs, timelines. and then some medical literature and textbooks. >> so were you the medical examiner who investigated or did the autopsy around the death of george floyd? >> no. that was dr. andrew baker, the hennepin county medical examiner. >> do you know dr. baker? >> i do. he was a pathology resident when i was on staff at hennepin county many years ago, and then we needed his fellowship i was one of the staff people there. and then after our offices merge
i worked with him again at hennepin county. >> so would you have been part of his training in his early formative years? >> yes. >> you consider him a friend? >> i do yes. have you talked to him about this case? >> no, not since right after it happened. >> but you did review his report? >> yes. >> as well as mr. floyd's medical record? >> yes. >> did you review the history of terminal events on may 25, 2020? >> yes. >> so -- >> what was kind of unique of what was absolutely unique in this case was the volume of materials i had to review. i have never had a case like this that had such thorough documentation of the terminal events. >> and by what of the thorough documentation, what makes it so thorough, in your opinion? >> well, the use of videos is
unique in this case. certainly as medical examiners we use videos but there's never been a case that i've been involved with that had videos over such a long time frame and from so many different perspectives. >> are you aware then of dr. baker's conclusions then on the manner of death? >> yes. >> your honor, i would like to show exhibit 193 that has been stipulated subject to dr. baker's foundation. so first, dr. thomas, what do we see on exhibit 193? >> this is a copy of the certificate of death of mr. floyd. >> okay. and so if we could highlight just through the word underlie.
just to make it a little bigger. based on your review of the evidence and the death certificate, do you agree with dr. baker's determination on the cause of death? >> yes, i do. >> and is that by the word immediate on here? >> yes, cardiopulmonary arrest subdual restraint and neck compression. >> thank you, dr. thomas can form an opinion about the mechanism of death? >> yes. >> would you tell us what that is? >> if we talk about naturally discuss that with us? >> yes. >> the example of a natural matter a death will be a heart attack? >> yes. >> if we talk about that axial cause of death, where would drug overdose fit in general as a
cause of death? >> usually drug overdoses are accidental enlisted evidence of intent in which case it would be suicidal. >> so we know what suicide is. and i'm determined if the medical examiner can't tell which of these it is what it is, then and undetermined is what you would indicate? >> exactly. >> so if a manner of death has been determined to be homicide, does that in your opinion as a medical examiner ruled out at death by accidental drug overdose? >> yes. >> now, brett, let's go back to exhibit 952. let's admit it for demonstrative purposes. doctor, , we were talking about the designation of homicide.
>> yes. >> and tell us what this guy 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 you want to look at that. >> so, but this is guidance given from the national association of medical examiners to medical examiner? >> exactly. >> and it provides guidance and guidelines on how to designate a manner of death us homicide? >> yes. >> so brett, if we could go to the next slide. so doctor, could you read this in 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 below. it is to be emphasized that the classification of homicide for the purposes of death certification is a neutral term and neither indicates no implies criminal intent, which remains a determination within the province of legal processes. >> and you agree with his? >> absolutely. >> as a guideline to follow? >> yes. >> and have you followed this kind of a guideline for the years you've been in medical examiner? >> yes. >> is there more guidance given from the national association of medical examiner guidelines on what constitutes voluntary act? >> yes. >> if you could click one more, brett. so dr. thomas, could you read this for? >> in general, if a person's of death result of hands of another who committed a harmful volitional act directed at the victim, the death may be considered homicide from the death investigation standpoint.
and then, although there may not have been intent to kill the victim, the victim died because of the harmful, intentional, volitional act committed by another person. thus, a manner of death may be classified as homicide cousin 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 are applying that we saw in these slight? >> 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 would like to get your perspective as a pathologist and
it medical examiner come this respect. are you aware of any such thing? >> yes. >> do you agree generally what the research that comes to the conclusion that the prone restraint is not dangerous for respiration? >> in certain laboratories settings that may be true but i do not agree with their applicability to real-life situations. >> if you could generally characterized for the jurors what's the punchline of the studies, what do they show? >> they purport to show that putting someone in a prone position even with some restraint and with weight on their back is perfectly safe. >> and do you find these studies to be reliable? have you found them controversial? >> well, i think they are fine for laboratory purposes but they
bear no resemblance to real-world situations. so i would say they are irrelevant for purposes of what you're talking about here. >> so how do they then not relate to the real world? what is artificial about them? >> 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 scared or uncomfortable, all they have to do is say stop. and that has happened in some of the studies that a a couple oe volunteers that said wait, no, i can't tolerate being indisposition, it's too scary. so that to me immediately takes up that whole element that we were talking about about the tear, the physiologic stress. so that's number one. number two is they are healthy
volunteers. these are young people who have mostly in 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, they are put on like a gymnastics mat to be facedown. so it is completely different when you are squished between a person and the hard ground versus having an evenly distributed weight on your back and you are 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 any point they had significant respiratory or cardiac difficulties the study would have stopped. and the person volunteering knew that. so to me it just, there's no resemblance to what mr. floyd experienced. >> did any of the studies involved a knee on the neck of any of the volunteers? >> no. >> any of them go on for as long as nine minutes and 29 seconds? >> 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. >> so any relevance to george floyd at all? >> not in my opinion, no. >> dr. thomas, have you done any calculations or kind of work of your own to measure what this of
dual and within the on the neck and the back of george floyd would have done to his oxygen reserves or lung capacities? >> no. that would be something i would completely defer to a pulmonary doctor to address. >> 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 it 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.
>> good morning, , dr. thomas. >> good morning. >> how are you today. >> good. >> nice to see you. you described being a forensic pathologist assorted being the doctor's doctor, right? >> general pathologist is considered that, yes. >> and the forensic pathologist in terms of a death investigation yet you kind have to wear many hats, right? >> yes. >> you have to have broad familiarity with multiple medical conditions, right? >> yes. >> sometimes medical conditions may appear at autopsy that you have never seen before? >> yes. >> right? some strange disease that you have never seen, right? >> yes. >> and you will speak to other doctors, right? >> yes. >> you will gather information
and share that, they will share information with you to help you conclude, make conclusion in an autopsy? >> yes. >> you also described having 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 knew the decedent, , right? >> yes. >> and ultimately the medical examiner's office compiles a massive amount of information itself about the cause and manner of death, right? >> yes. >> and you 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 come after you prepared your report have you been provided with additional materials that may be relevant to your considerations? >> not that i i can think of f the top of my head. >> okay. we will come back to that. i just -- but you did have an opportunity to review dr. baker's entire file? >> yes. >> i believe we'll be hearing from dr. baker later this morning, or this afternoon and will have questions for him. i would like to follow up on some of your conclusions.
there is a term used in dr. baker's autopsy, the cause of death, the term complicating. >> yes. >> can you define medically speaking what the term comp locating means? >> all, 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 subdural over restraint and compression -- subdural.
>> have you been provided with dr. baker's information about dr. baker's opinions in this case? >> nothing very specific. i mean, just what he put the autopsy report and all 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 is a reasonable degree of disagreement amongst comp 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. >> that was dr. baker did that, right? >> yes. >> and you know dr. baker left? >> yes. >> and you know he did a competent medical examiner? >> yes. >> he's the chief medical examiner for hennepin county at this time? >> yes. >> now come you provided a given with all of the information from this 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. >> and would you explain or would you describe that as an enlarged heart? >> i would say it is a slightly enlarged heart, , yes. >> there are some different measures of how to base an enlarged heart or how to determine the carcass enlarged,
right? >> right. by some categories that heart would not be considered enlarge enlarged. >> so there's tonight as i i understand it two different kind of primary measurements or primary ways of comparing mr. floyd's heart to determine if it is a large, right? the melena studies and a northwestern studies? >> oh, oh, i see. oh, there are probably multiple ways of looking at heart weight. i mean, those are two of them. as a study from the mayo clinic. there's one in europe. yeah, there's lots of ways i think. >> but ultimately based on all of your information you would agree that mr. floyd's heart was slightly enlarged? >> yes. >> in terms of the demaio and melena standard, but with a normal mail heart -- mail heart
way similar to mr. floyd? >> i don't know at the top of my head. >> we do disagree if i i wereo say was 383 grams? >> that will could be. >> for the average, , human. >> for the average, right. >> yes. >> so according, if that were the average heart rate or heart size, excuse me, heart weight, 383 g, three grams, relevant to mr. floyd's heart, mr. floyd's heart would be considered profoundly enlarged? >> well, the think about using averages especially medicine which is of course what i most annoyed with is we don't generally say, we don't generally just convert to an average people usually convert to an average plus and minus two standard deviations. that's why the range that i usually use is from
253-510 grams would be the range of normal for someone of mr. floyd's height. and so i don't know in the demaio melena study what their standard deviations would be. but i wouldn't use just the average. >> and so in terms of your come how you would assess the weight or size of the heart you would say 510 grams is the high, 510 g ten grams is high in? >> right. >> of that come and 540 is, exceeds that, right? >> right. >> 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 the person to have an enlarged heart? >> probably the primary cause is high blood pressure. >> you understand based on mr.
floyd's medical records i 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 i mentioned supply blood and nutrients to the heart muscle. there's left in right and then the left branches into the left anterior descending and the left circumflex, and then there's the other branches off that. >> how would you describe a link or stenosis of the coronary arteries? >> so the way we as forensic pathologists describe it is we look at the opening. so if an opening is fully open and that would be 0% narrowing, and if it's completely close and that would be 100% occluded. so then we look at anything
ranging from 25, 50, 75, 90%. it's just an eyeball estimation. we don't actually get up 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 of 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 inordinate is called proximal to the aorta, and in 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 that if you have distal narrowing. >> another way of saying that we be it decreases the event of blood the heart is getting, right? >> yes. >> and it also affects how things are removed from the heart, right? carbon dioxide. >> well, that's different. that wouldn't happen from the blood vessels coming in, i don't think. so i, i wouldn't include carbon dioxide in that. >> 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
70-75% is in the view of a forensic apologist something that in the absence of another cause of death could be used to explain death -- forensic pathologist. >> it's also true people live with 100% occlusion and go on and do fine. you have to understand this is strictly my perspective as a music pathologist and everyone i see is that, so that's kind of a different perspective. >> can you explain what myositis mycosis is? >> the myositis is a a name oe heart muscle cells, so site means sell and it means muscle. so we have a heart, my site, it's the heart muscle cell. and necrosis me to death. so if you see my own site necrosis that means that are
dead heart muscle cells. >> and yet have necrosis to cause sudden death? >> no, you don't have to have necrosis. >> and would you say that hypoxia is absence of oxygen, agree? >> yes. >> and can hypoxia part cause sudden death by other means? >> hypoxia means low oxygen, sorry, and your question is can the 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 heart beats, the love deb, is that there are electrical currents that go through the heart muscle.
and normally there is a certain sequence in which heart muscle, muscles will fire. that's called the conduction system to which the electrical impulses flow. that's what keeps the heart beating in a regular rhythm, beat beat beat. yeah, that's the conduction. >> so what happens if the conduction system is impaired? >> then you can get what's called an arrhythmia or abnormal beating of the heart. >> that can result in sudden death? >> it can, yes. >> which artery supplies the kind of, that pacemaker of the heart? >> oh, it probably is variable from person to person. i mean i think the coronary artery and we consider the most important usually is the left anterior descending coronary artery but there's a lot of
individual individuals. >> what about the right coronary artery? >> that i mean, it really depends on any given person which part of the heart is supplied by their particular distribution. >> okay. and in mr. floyd's autopsy, the right coronary artery dr. baker determine had a 90% occlusion, correct? >> 90% narrowing, yes. >> when someone is exerting themselves does that make the heart work harder? >> yes. >> doesn't mean that more blood oxygen -- does that mean 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, the physiology of that in your consideration, right? >> yes, the physiological stres 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 were 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 occluded right coronary artery, right? >> narrowed. >> 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 am going to ask you a hypothetical. let's assume you found mr. floyd did 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 a pharaoh sclerotic
cardiovascular disease? >> probably thousands of times, yes. >> similar degrees of narrowing of the artery? >> yes. >> have you ever certified death due to hypertensive cardio -- i'm trying to -- >> yes. hypertensive . hypertensive cardiovascular disease, yes, absolutely. >> with a heart at this weight or even smaller? >> well, it was again in this setting where that was the old 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, i didn't take
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. >> you discussed the abrasions that you saw and the jury saw pictures of. you would agree that the abrasions are in the left to right pattern? >> meaning there are more on the left than on the right? >> right. >> on his face yes. on his shoulder yes. anthony had the abrasions on his right hand. >> and even in terms of the pattern of the abrasion, up and down, like an abrasion to go from the bottom of my body up or he 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 at least some of these abrasions occurred would be when mr. floyd was initially put down on the ground? >> i, 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, what cause the abrasions, right? >> right, right. >> and if someone was being held down with the weight of three people, would you expect those to be more punk tile in their nature or like, you know, with the line movements.
>> oh, gosh, there are too many variables there i would say. >> now, you ultimately determined that this case was asphyxiation essentially? >> yes. that was the primary mechanism. >> and association is simply a lack of oxygen to the brain? >> yes, low oxygen, inadequate oxygen. >> inadequate oxygen to the brain specifically. >> yes. >> in terms of asphyxiation come you would agree that there are multiple things that could cause asphyxiation? >> yes. >> so use the reference to someone being strangled, right? >> yes. >> if i came up to and i strangled or i strangled a person, put my hands around the 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 but -- >> those would be things like a broken hyoid bone?
>> yes. >> damaging to discuss? >> yes. >> and in a six-year death, there are often times frequent those types of signs available, right? >> it really depends on the mechanism of asphyxia. >> let's go back to the mechanisms of a six-year period you describe strangled would be one, hanging could be one. >> yes. >> you have described positional or mechanical asphyxia. >> those are types, yes. >> positional being based on the position of the body. mechanical being something, using some sort of a device to a 60 someone? >> oh -- to asphyxiate someone. >> we haven't really talked about positional and mechanical. there's all kinds of things under both of those can cause low oxygen. >> one of the things that can cause low oxygen to the brain is use of controlled substances,
correct? >> well, eventually yes. yes. >> so someone can and just a particular type of a controlled substance. that particular substance could affect the diaphragm, right? >> it affects some controlled substance affect the ability to breathe which it then decreases the oxygen which then leads to low oxygen, yes. >> and that is essentially what you are seeing is that in this particular case as i understand, looking at your notes, 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 is essentially what a 60 is, generally. >> inadequate oxygen, yes.
>> you asked a series of questions about some studies in terms of i think they are called -- out of san diego? >> yes, dr. chan. >> right. are you familiar with the journal of forensic and legal medicine? >> yes. >> you testified some of the problems with the chan studies were that they were in laboratory settings, that they were controlled environments, healthy individuals, et cetera, right? >> yes. >> are you familiar with the work of dr. christine hall and her paper incidence and outcomes, prone positioning following police use of force any perspective consecutive cohort of subjects? >> is that the one from canada? >> yes. >> yes. >> that was essentially analysis
of actual lease encounters, correct? >> yes, in canada. >> understood. but they actually, that study, they go through and a look at the number of police citizen interactions, correct? >> yes. >> and then from those police citizen interactions they further go into look at how many involving place in the prone position or a non-prone position? >> correct. >> they consider various actual real-life variables, agreed? >> yes. >> 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, , what is it, about 3000 prone positional placements? placement? >> yes. >> out of a total of like
1.1 million police interactions. >> yes. >> so 1.1 million police interactions resulting in about 3000 prone position, prone position of arrests, that these are real people, real incidents, right? >> yes. >> and in those 3000 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 deathlike this, how did they -- it utterly baffles me which i kept saying canada. because i think, i don't know what's different but -- >> objection, nonresponsive. >> so the -- let me ask you in terms of hypoxia.
can you again to find hypoxia? >> low oxygen. >> and which organ is more sensitive to the lack of oxygen, the brain -- >> the brain. >> the brain is the most, it needs the most oxygen, right? >> yes. >> that is because it is doing millions of things simultaneously, right? agreed? >> yes. i'm sure there's lots of reasons metabolically why. >> i think a previous witness testified that it takes about 20% of bodies oxygen supply to function, right? >> that sounds about right. >> but hart also needs oxygen, right? >> yes. >> so in terms of the professional standards for determining asphyxia death, is it true that you have to first
exclude all natural and nonnatural cases or causes of death? >> well, you can have natural and nonnatural causes of low oxygen. i'm sorry, i guess i don't understand. >> sure. there's a criteria that is established for making a determination of positional asphyxia as the cause of death, right? >> well, i, i'm not really sure what, i'm sorry, i don't understand that. >> fair enough. is there 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, is use? >> correct. >> and in the 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? so the prone position, i'm just talking generally speaking, no other factors, prone position in and of itself is not inherently dangerous, right? >> correct. >> is the prone position on concrete inherently dangerous?
>> again, with no other factors, as long as someone can breeze, no. >> i could be lying by the pool in florida, right? >> right. >> on my stomach in the prone position not inherently dangerous, right? >> right. >> do you know or did you take into consideration mr. chauvin's weight in your analysis? >> all, i'm aware of his weight. i would say i took it into some consideration but it wasn't a major factor when we or the other. >> you reviewed all of the videos, right? >> yes. >> it's fair to say that
portions of his weight were placed on mr. floyd's body at aa different distribution? >> yes. >> and ultimately in terms of the autopsy, dr. baker conducted, in terms of the area in the shoulders, the back and the neck, no bruising was found, right? >> right. >> and in your experience as a forensic pathologist if someone is placing a significant amount of weight on a persons 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 next very of mr. floyd? >> correct. >> there is no bleeding into the
muscles in his back? >> correct. >> you would agree that the knee is sort of a pointy or a more protuberant part of the body? >> i guess so. kind of flat on the top because of the patella. >> and we talk about the shin, the shinbone, the shin bone itself, there's not a lot in between the skin and the shin bone, right? >> that is true. >> and it is 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 the kneecap. >> right.
>> you have reviewed obviously a lot of strangulation type cases in those, and your career? >> yes. >> strangulation with the hands, right? >> primarily manual but also ligature. >> ligature be like our rope or a phone quarter stomach? >> exactly. >> and in this manual strangulation cases the pressure that is exerted in that will frequently leave bruises, fingerprint size bruises, right? >> frequently not always. >> and ultimately what increases the likelihood of seeing a bruise is the amount of force that is applied, right? >> you know, i don't know what all the factors are, whether its 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. >> so -- >> everyone bruises gently. >> so yesterday depends on what medications they may take. >> right. >> yesterday there was an analysis or an analogy to sitting on a church bench and you don't bruise your behind. >> and that -- [inaudible] [laughing] >> would be different if you're sitting on a church bench under, with a baseball, for example, underneath your buck? >> 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 fight hypoxic 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 but you are describing lack of ischemic changes in the neurons? >> correct come in the brain. >> correct. because that has to happen over a period of time. >> okay. and when someone is experiencing that shortness of oxygen or the 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 observe every complaint of these comp any visual changes? >> no. >> did he appear to be confused to use? >> so what i guess what time. are we talking about? sorry. >> that helps. maybe if we narrow down the time. in 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? >> while i mean did he come he was articulating that he was in
pain, right? >> yes, and then he couldn't breathe and he called 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. i -- >> did he appear to be breathing during this timeframe? >> not effectively. >> d you know how many breaths per minute? >> no. >> if one expert indicator it was a rate of 22 breaths per minute -- expert indicated, 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 -- >> at least for the first five minutes or so mr. floyd was talking, right?
>> well again speed is talking, yes or no come he was talking. >> he was, yes. there were words, yes. >> so he had an open airway. >> yes. >> you would agree that, or would you agree that at some point he went limp? >> yes. >> and would you describe what you saw as a progression of hypoxia in that instance at the point he goes live? >> that is certainly a good explanation for it -- goes limp. >> good explanation for it, yes. >> it was not a a sudden hypoc event, right? >> that is my interpretation, yes. >> you would agree that if he was progressively growing hypoxic you would expect whole body hypoxia?
>> i will rephrase my question. >> yeah, sorry. >> i'm not a doctor so i have to rely on my notes. so if you was progressively suffering from whole body hypoxia, the brain would be the first thing that would have come show signs of hypoxia? >> 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 the 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 will use that word global. >> whole body. >> i i mean, if there's inadeque
oxygen the blood flows everywhere so i come i guess that's what you're talking about. >> but the brain is the first thing to show symptoms of -- >> right, the brain is 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 caused the work, caused
cause the heart to work harder? >> yes. >> and increases the hearts 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? >> are you asking that same question about as a forensic pathologist to what degree of narrowing do we think potentially fatal? >> yes. >> seventy, 75% and above. >> now, in terms of drug use, you obviously were aware of the toxicology that mr. floyd had certain drugs in his system, right? >> yes. >> so we sit on boards that that needs in the system. >> yes. >> okay.
-- when we say on board. >> 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 indirectly -- indirectly? >> i've heard of that come yes. >> and that speeds up this vision 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, right, and there put in an ambulance and taken to the hospital for resuscitation,
they are often, there is ivs that are placed in a person, right? >> yes. >> and those ivs contain sailing? >> yes. >> and saline can ultimately dilute or decrease to some degree the amount of controlled substances that would be met as they would be measured? >> that a theoretical possibility. >> you would agree that no is a respiratory depressant, right? >> it slows breathing and lowers oxygen in the blood? >> it, yes. ..
>> exactly does it exclude him takingfentanyl more acutely or recently ? >> know, there's no way of knowing the timing . >> until the pressing the respiratory system and also act with the pulmonary artery , interacting with coronary disease, correct ? >> can you clarify that? >> does into nose depression of the respiratory system also act with coronary artery disease and carbon dioxide to reduce its supply to the heart? >> as fentanyl may lead to a gradual progression of slowing breathing, and ultimately decrease the
oxygen, that would apply to oxygen of the brain as well as theheart . >> and it would likewise increase the carbon dioxide? >> yes. anything that decreases respiration decreases exchange. >> so as that exchange process is happening, you're not taking in the oxygen, likewise not expelling the carbon dioxide. >> right. >> the carbon dioxide will increase if you're not expelling it. >> correct. >> you would agree methamphetamine is astimulant . >> correct. >> and that can cause cardiac arrhythmia. >> it can. >> and it can increase a person's heart rate. >> it can. >> you testified before that methamphetamine, there's no safe level of methamphetamine
. >> correct. >> the fact that methamphetamine is a lower toxicological standard doesn't somehow makeit see . >> right. >> doesn't exclude the possibility that it could increase the heart rate. >> it could. >> be, in terms of the evidence in this case, were you made aware that drugs were found in thebackseat of the squad car ? >> yes. >> and those drugscontaining the dna of mister floyd . >> yes. >> and those drugs were at least to some degree partially dissolved . and that those drugs were a mixture of fentanyl and methamphetamine. >> yes. >> on the toxicology in this
case, did you see any metabolic bipolar product of methamphetamine western mark. >> know. >> that means that methamphetamine was taken more recently in time ? >> probably. there's lots of variables. >> again, just taking into consideration removing certain variables, you find a person at home, no struggle with the police. and the person doesn't have a heart problem yet you find fentanyl and methamphetamine in this person's system at the levels they are, would you certify this asan overdose ? >> again, in the absence of anyof these other realities . yes, i could consider that to bean overdose . >> and the level of fentanyl
in a person again, in this hypothetical scenario, there are certified as drug overdose significantly lower than 11 nanograms per milligram? >> lower, higher. it's got a huge range. >> as well as i believe as we percent or three nanograms. >> so the ingestion of drugs is unique to that individuals body. >> right.
>> i have no furtherquestions . >> doctor thomas, a few things i'd like to try to clarify with you. you were asked a number of questions that were to the effect that if we take the police sub dual restraint and compression out of this, what was you the cause of death? remember those questions? >> yes. >> those questions a lot like asking mitchell lincoln, if we take john wilkes booth out of this, >> argumentative. >> doctor thomas, if we put the police sub dual, compression and compression of this restraint, what was
the cause of that matter of death for mistergeorge floyd ? >> because of death was the law enforcement so dual, restraint. >> doesn't make any sense to you whatsoever from the standpoint to assess cause and manner of death for mister floyd to be answering questions having to do with hypothetically taking the facts of this case out relating to his full restraint and nextcompression ? >> leading the witness sir. >> doctor thomas, from your standpoint as a forensic apologist, and your analysis of mannerand cause of death , would you ever approach a assessment of manner and cause of death taking out of it the factthat you found relevant to assessing and determining the matter and
cause of death ? >> no. >> in this case those factors are what? >> the law enforcement so dual, restraint and compression. >> you asked questions again about fentanyl and meth. remember those questions? >> yes. >> do you know whatquantity of meth was found in mister floyd's bloodstream ? >> i have a number but it was very small. >> this was the point, that it was a very small amount. were you able to assess based on the amount what kind of defect if at all it would have on the stress and strain on his heart? >> no, there's too much individual variability to correlate one number with one person's reaction. >> so so with respect to fentanyl, if there's a punchline we can get to with respect to fentanyl, fentanyl has been discussed with you doctor thomas as a
respiratory either depression or suppression. >> yes. >> in order for us to go from fentanyl to death, in the middle there's certain symptoms and responses and reactions to a person would have to was suffering from fentanyl overdose or intoxication. >> yes. >> if the person doesn't have those symptoms, those indicators, then would you feel that it's possible either to conclude they are suffering fromantenatal intoxication or overdose ? >> know, if there's no signs of fentanyl overdose, then it makes no sense to conclude that there was anoverdose from fentanyl . >> to be clear for the ladies and gentlemen of the jury, what are those things fentanyl overdose or intoxication?
>> so fentanyl is an opioid. it's like morphine orheroin . and it causes flowing, first of all it's a potent pain medication given mostly for that but it also involves slowing of the respiratory rate. in a very gradual peaceful, non-struggle kind of way. what is described as people just falsely and made just kind of slumped gradually over because they very peacefully stopped breathing. or it slows and then eventuallystops . >> and they fall into a sleep out of which they can't even be aroused . >> correct. >> with that also be known as a,? >> yes, ultimately it's, >> when george floyd was on the ground for the nine minute 22 seconds, was he
asleep tothe point of not being able to be aroused ? >> not for the first half, no and afterwards, it was completely unresponsive but that's different . >> for the second half is unresponsive with nobles. >> exactly. >> was joyfully during the nine minutes 29 seconds: you saw? >> no. >> when we talk about fentanyl overdose, did you ever see as applied to george floyd, during the nine minutes 22 seconds, did you ever see as relates to fentanyl overdose during the nine minutes 22 seconds that he was on the ground and during the sub dual and restraint by mister chauvin, that he ever exhibited any of the symptoms of until intoxication? >> no.
>> you asked again quite a few questions about the heart . and i remember that discussion. i think it was to the effect the heart was slightly enlarged. high blood pressure, narrowing of the coronary artery. dead art muscle cells. i canrecall all of that . in order for us to go from there being issues with damage to the heart, to a death from damage to the heart, in the middle, do we have to have certain cardiac events then lead to death. >> yes. >> would you tell the ladies and gentlemen ofthe jury if were going to talk about heart conditions ,what are those conditions in the middle that lead to death . >> ultimately leads to death is an arrhythmia, and abnormalbeating of the heart . and as i described, it's generally called, is often called a sudden cardiac arrest because it's sudden and someone just trots over.
>> to be clear, when were talking about this these heart conditions and a sudden cardiac arrest, fatal arrhythmia, did you see any of the indication in all this discussion about heart conditions at mister floyd ever suffered from a sudden fatal cardiac arrhythmia as the primary cause of death. >> no. >> it was in evidence mister floyd suffered from aheart attack . >> no. >> if you bring to mind what was found during the autopsy, was there any injury to mister froissart whatsoever, >> no. >> so if we talk about for example dead heart muscle cells. any dead muscle heart cells on autopsy. >> not that baker described not that i saw. >> in fact his heart was so
ordinary in terms of noninjury it wasn't even photographed intact. >> doctor baker took one photo that showed no art and no acute injury. >>. >> you were asked about certain studies out of canada , on the prone position. and about, and the findings out of canada supposedly with real police settings, with no fatalities. >> are you familiar with any studies reaching that conclusion out of the united states of america ? >> no. >> what is so peculiar about canada that were talking about canadian studies. >> that's what i don't understand. i mean, i filed that study and i just thought i don't know how tointerpret this . it's just so contrary to the actual experience of forensic
pathologist in the united states. >> you asked questions about whether prone position is safe to lay on your stomach. >> yes. >> are you familiar with whether or not laying in the prone position automatically brings about a reduction in the oxygen reserves, somewhere in the neighborhood of 20 to 24percent . >> i am not aware of that i would defer to a clinician. >> perhaps a pulmonologist. >> that would be the best. >> i think you were in effect asked the question about laying by the pool on my stomach in florida. >> yes. >> george floyd was not laying by the pool on his stomach in florida . >> no. >> i know the answer to this
but i'll ask the question about sitting on the church benchwith a baseball under your butt . you've never done that. >> no. >> your asked questions about symptoms of damage tothe brain . >> yes. >> and whether there wasany evidence of damage to the brain . would you tell the ladies and gentlemen of the jury whether the fact that you observed and anoxic seizure, was that evidence of damage to the brain ? >> what happens in the brain is when there is inadequate oxygen, we by causing this anoxic seizure that we've
described. if someone then goes on and essentially is brain-dead but their heart can be restarted and there kept alive for say a day and then they die, then you will see changes in the brain. but in a case like mister floyd, he died during this training time and his heart was never able to be restarted. that is not enough time for the brain cells to show any kind of reaction that you can see at autopsy. >> thank you doctor thomas. >> doctor thomas, after the heart stopped, if a heart stopped is it possible that the body will continue to breathe? or was fire?
>> yes, i suppose it could just circumstances. >> that continued respiration after a heart stops to be a matter of a minute or two. >> i suppose that can happen. >> you would agree methamphetamine also further constricts the arteries, right? >> they tend to. >> and it so that constriction, there's been a lot of discussion about the level of methamphetamine in the system, this low level as it's beendescribed . >> you said there's no safe level, agreed western mark. >> would you as a physician, prescribe methamphetamine to a person who has a 90 percent or 75 percent occlusion to his or her heart? >>.
>> you may enter an opinion in that regard. >> idon't have an opinion . >>no further question . >> thank you doctor. we will reconvene at 1:30. >> it is the 10th day of the trial of derek chauvin, former minneapolis police officer charged in the may 25 2020 death of george floyd wrapping up the testimony there, doctor lindsay thomas, rinsing biologist and he we will hear later today from further medical experts including possibly today doctor andrew baker . who is the medical examiner of hennepin county reminder our coverage today will re-air tonight beginningat 8:00 eastern . you're on c-span2 and all of
our previous days coverage available for you at c-span.org. we expect them to return around 2:30 eastern, 1:30 central and i live coverage will resume a gavel back in until then to show you the testimony from earlier today from doctor thomas. >> call the next witness. >>. >> good morning your honor and counsel. state will call for our first witness, doctor lindsaythomas . >> you swear or affirm under penalty of perjury the testimony are about to get will be the truth and nothing but the truth . >>