into the evaluation matrix, the puzzle of all of the information that you are trying to include. as well as toxicology and microscopic and the glass slides. some cases can take to to three months. there's a requirement that you should complete 90% of your cases within 90 days. otherwise, you cannot be accredited. they prefer you to do it within 60 days. but 90% of cases should be completed within 90 days. that's three months. the 10% of cases that aren't completed, are going to be very complex cases. often the deaths in custody and the pediatric sudden deaths are the ones that fall into that 10%. they off gone out further as you

gather all of that information. >> thank you. can you explain what the death certificate? ultimately, a death certificate is issued, right? >> correct. >> can you explain what the death certificate is? >> the death certificate is a document that is produced by a physician. the greater majority are signed out by physicians within the hospital or nursing home when people die of natural deaths. medical examiners are usually exposed to about 25% of deaths within their jurisdiction. the death certificate is a certification that the person has died and within a reasonable degree of medical certainty the certifying physician believes whatever is on the cause of death line is the cause of death, within a reasonable degree of medical certainty. >> let me ask you in terms of this particular case, you reviewed a substantial amount of

information? >> yes. >> can you just briefly describe the information you have reviewed in this case? >> gosh, it goes on for several pages. but there are medical records, the records that occurred in the hospital at or about the time that mr. -- the attempted resuscitation of mr. floyd occurred, there are ambulance records, multiple police records, toxicology information, there are multiple videos from multiple sources, body-worn cameras, surveillance videos from stores and other facilities in that area. there was video material from observers that is available. there's the toxicology data, autopsy information, the autopsy photographs, the microscopic examination.

it goes on and on and on. there's a substantial amount of information on this case. >> before we get back to the death certificate in this particular case, upon your review and based upon your training and education, your experience as a forensic pathologist, have you formed opinions in this case to a reasonable degree of medical certainty? >> yes. >> we will come back to those shortly. in terms of the death certificate, are there two parts to that? >> yes. >> can you explain those two parts? >> the first part is what the physician believes to be the cause of death. that is something that you will put what we call part one. it's what the cdc refers to it. the death certification is controlled and governed by the cdc. each state will have a slightly

different format to the death certificate and the way they do things. guidelines that are put out there by the cdc for completion of death certification are certainly ones that are national. >> what's the first part of the death certification, according to the cdc? >> the first part is, the primary cause of death. >> what's the second part, per cdc? >> are there things contributing to death but not directly related to what's in part one. >> i am going to ask -- i'd like to show exhibit 193, which is in evidence. do you see that in front of you? ask to publish. you are familiar with this document? >> i have seen this document, yes. >> what is the first part of the

certification of death? >> the first part here, the cause of death is cardiopulmonary arrest complicating law enforcement restraint and neck compression. >> under that there's a phrase that says underlying. is that what you are talking about in terms of the second part per the cdc? >> no. the way the cdc normally phrases it is, you can break it out into multiple lines. it could be cardiac arrhythmia due to such and such, due to such and such. that's where the underlying conditions come into the death certificate. at least when you look at the cdc guidelines and the death certificates that i'm used to completing. the second part that i refer to

as part two, on this death certificate it's called other contributing conditions. >> what are the other contributing conditions that you reviewed here? >> so on this particular death certificate, the certification says that fentanyl intintoxicat and methamphetamine use. >> this was prepared by dr. baker, correct? >> yes, that is my understanding that he was the individual who certified this case. >> in terms of dr. baker's analysis of this case, how did the heart and drugs contribute to the cause of death? >> they were significant -- they contributed to mr. floyd having a sudden cardiac arrest, in many

opinion. that's how i would read it. >> okay. i'm going to take this down. if we can unpublish. did you prepare a powerpoint presentation to walk through your opinions in this case? >> yes. >> judge, i identify this as demonstrative exhibit 1098. i would move to publish. >> any objection? >> no, your honor. >> it's received for that purpose alone. >> before we begin, doctor, can you summarize briefly what your opinions are in this case? >> yes. so in my opinion, mr. floyd had a sudden cardiac arrhythmia or

cardiac arrhythmia due to his hypertensive heart disease. you can write that down multiple different ways. during his restraint and subduing and restraint by the police. his significant contributing conditions would be -- since i have put the heart disease in part one, he would have the toxicology, the fentanyl and methamphetamine. there is exposure to a vehicle exhaust. potentially carbon monoxide poisoning or an affect from increased carbon monoxide in his bloodstream and the other natural disease process that he has. all of those combined to cause

mr. floyd's death. >> let's walk through each of these, if we could. starting with the opinions of dr. baker as far as the cardiopulmonary arrest, before we do that, if we could publish the exhibit, your honor. can you describe what this is and why it's relevant to this case? >> so this is a document that is produced as a guide for medical examiners to use when certifying the death and specifically the manner of death. >> what is the manner of death? >> the manner of death is how did the cause of death come about, and you have five

different choices that you can check off or write down on a death certificate as to the manner of death. >> does this document specifically address asphyxia death, positional asphyxia? >> it addresses all sorts of manner of death. again, it's a guideline put out there to assist medical examiners. not every case cleanly fits into one category or meets the criteria for the guidelines. >> let's talk about in terms of the second slide, positional restraint. how do they deal with death investigations involving potential positional restraint? >> the recommendation is that -- it's not a recommendation. they say, you may be classified as a homicide. doesn't say shall or should.

it says may be classified as a homicide. we have to recognize that these are medical guidelines. it then goes on. everybody, i think, can easily read that. if you want to go back one. in such cases, there may not be intent to kill. but the death does results from one or more intentional, volitional potentially harmful acts directed at the decedent without consent. there's some value to the hole homicide towards reducing the perception a coverup is being perpetrated. >> in terms of the five manners of death that you described, again, we have heard testimony or the jury has heard testimony from other experts who have testified. there's homicide is one,

suicide -- can you describe the other snz. >> homicide, suicide, accident, natural and then undetermined. >> can you describe what undetermined means? >> according to the guidelines, undetermined or the other term on some death certificates is could not be determined is a classification that's used when the information pointing to one manner of death is no more compelling than one or more other competing manners of death. in thorough consideration of all available information. >> the guidelines also define homicide? >> yes. >> again, homicide occurs when a death results from a volitional act, an act a person did, 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 a homicide. more below. it's to be emphasized the classification of homicide for the purposes of death certification is a neutral term and neither indicates nor implies criminal intent, which remains the determination within the province of a legal process. >> why is that second part important? >> because this is a medical opinion that is on a death certificate. the manners of death are unique or virtually unique to the united states of america. these were put on the death certificate by the center for disease control in order to gather information as to how americans died or die for epidemiological purposes and to study and try and prevent deaths. they are not meant to usurp any

legal process. in fact, in many circumstances, regardless of what the medical examiner puts on a death certificate in the way of manner, the legal system can and will act in a completely independent and different format. >> again, we discussed a little bit about the cdc death certificates, the instructions. is this the guideline by the cdc? >> yes. >> to enter all diseases or conditions contributing to the death that were not reported in the chain of events? >> in part one. in the first part, yes. >> if we can take this down for a moment, your honor. with respect to dr. baker's autopsy, i just want to talk a little bit about the cardiopulmonary arrest he

references. what are the findings that were relevant to your analysis in this particular case? >> there are substantial pertinent negatives in this particular case that drove my opinion. >> what about the size of the heart? >> there are certain pertinent positive issues. mr. floyd's heart was enlarged. there are multiple methods and studies that have been done on the size of the heart in the united states. there's one study out of the medical examiner's office in san antonio where they took a series of individuals who died suddenly with trauma and hopefully eliminated as part of their process natural disease that might have caused alterations in

the heart size. >> excuse me, did you prepare a slide relevant to this? >> yes, i did. >> the study you were referencing. >> right. in their study, they found that 95% of males had a heart weight of between 233 and 383 grams. anybody outside of those limits -- you would expect about 2 1/2% to be lower and 2 1/2% to be higher. that's the 95% certainty on either side of the mean. that is what they proposed as being the reference range for adult males. >> how about the mayo study? >> the mayo study is one way you can go in and calculate the weight based on the size of the individual, which is potentially more accurate. because you don't really want to

take a 130 pound 5'5" male and say -- plug him into a particular range. you would expect their heart to be smaller as most of their organs would be smaller. mr. floyd was a very tall, robust looking individual. i would expect him to have a larger heart. the type of study such as the mayo study, where they put in the sex of the individual, male, the height and weight, and then come out with as part of that calculation accounting for that, the 95th inclusion rate would top out at 510 grams in this circumstance. mr. floyd's weight at 540 is outside this range. i will tell you, there are multiple studies. another one out of chicago and

northwestern university where has even broader range and would indicate that mr. floyd was within the 95 but still at the very top end of normal. bottom line is, he has an enlarged heart. >> if we could unpublish this, your honor. in terms of -- that's what you ultimately kind of see as relevant evidence here is that mr. floyd had an enlarged heart? >> yes. >> how does the size of the heart affect the blood supply, nutrients, oxygen, things of that nature? >> the heart is a muscle. it is dependent on the supply of oxygen, glucose and other important nutrients to function. when a heart or any other muscle grows in size, its consumption of those vital components

increases. mr. floyd's heart would have twice the need of those nutrients compared to a 260-gram heart or 270-gram heart. would be in the middle of the study criteria. because it's just twice as much heart muscle to support. each of those cells is bigger and requires more oxygen. >> it's like the law of supply and demand, right? >> correct. >> all right. what happens to a person when they experience a lack of supply, so to speak? >> like every other organ, the heart has certain reserves of energy built in. the typical amount of reserve in our brains is enough for us to

maintain consciousness for about 10 to 15 seconds. that's the organ most sensitive to constant supply. >> the heart or the brain? >> the brain. the heart is the next. like other organs, it will be able to maintain function even when the supply is reduced or even completely cut off. at some point, you do have to resupply. those reserves are -- when the heart is being exerted or being used, and you either have to completely replace it or if you are only partially replacing them, at some point you are going to exhaust the reserves. >> how do we replenish the supply? >> the replenishment comes through the coronary arteries. they bring blood into the heart. as that blood arrives, it delivers oxygen and other

nutrients. it also removes the byproducts of the metabolism of the heart muscles as they contract. >> what type of symptoms might someone show if they are diminished in their supply? >> at some point, there are a variety of symptoms that can result. you can feel your heart racing. you may even get palpitations. you get potentially short of breath. in some circumstances, you may start getting chest pain, what we refer to as angina. it can get worse than that. you can have sudden symptoms such as a collapse without any warning. there's a spectrum of different symptoms that can occur. >> when the supply isn't being met, what would a person customarily do to replenish the

supply? >> you know, when one becomes short of breath, you tend to ease up, back off, stop walk, stop running, stop exercising until such time as you feel like you have your heart rate down. some people monitor their heart while they are exercising to ensure they don't go over certain limits. different ways of doing it. typically, if you experience symptoms, it's your body telling you, slow down. >> what happens if someone doesn't do that? >> if you don't and you don't heed those warnings or you can't heed those warnings for other circumstances, the consumption of those essential metabolites goes on. the production of the products of contraction, which need to be removed, continues to increase. at some point, the heart will fail, have a sudden cardiac

arrest/arrhythmia. that's what you expect to see. >> within the field of forensic pathology, what would you call the stopping of the heart? >> we typically call it sudden cardiac arrest or cardiac arrhythmia. >> what's the difference between sudden cardiac arrest and arrhythmia? >> sudden cardiac arrest really is an observational situation. you observe the person suddenly stop functioning. usually, the background process is an arrhythmia of some sort. often starting out as aarrhythmd progressing progressing. >> what things might cause a heart to be bigger like mr. floyd's? >> the commonest someone in the united states, which is part of the developing world, is hypertension. what we would call essential hypertension. it just happens.

>> based on what you reviewed, did you determine whether mr. floyd had hypertension? >> the size of the heart would be extremely good evidence that he had hypertension. secondly, there are medical records that i did see where he had an elevated blood pressure, previous hospital or clinical interactions. there's evidence that he had that. then there was something else found at autopsy, a tumor, that is sometimes associated with hypertension as well. in certain people. >> that's the paraganglanoma? >> yes. >> we will talk about that later. generally, can you describe the major blood vessels of the heart? >> yes. the right coronary artery and

the left coronary artery. the left coronary artery, within a short distance of coming off the aorta divides into two major arteries, the left anterior descending and the left circumflex. some people call it three coronary arteries. technically two with one dividing into two. neither description would be incorrect. >> what is narrowing or stenosis of the arteries? >> narrowing or stenosis of the arteries means the arteries -- the inside diameter of that artery is smaller than it should be. it's being narrowed by a disease process. >> how does long-term drug use affect narrowing of the arteries? >> there are certain drugs that do cause advanced or more

rapidly advancing atherosclerosis. not just drugs but many substances. even smoking, for instance, is associated with earlier atherosclerosis. certain drugs and other substances can be added on to that particular -- even urban pollution has a risk of advancing heart disease. >> what specific drugs? >> well, in this particular case, methamphetamine, which was present in mr. floyd, has been associated with earlier onset of narrowing of the coronary arteries by atherosclerosis. >> you can describe the difference between proximal and distal narrowing of the arteries? >> right. the narrowing can occur anywhere up and down the artery. when it occurs close to its origin, a aorta,

that's proximal. further down the artery, it's distal. if you have narrowing close to the beginning of the artery, anything downstream from that narrowing is suggest to decreased supply of blood. if you have it further down and distal, then the first part and all the branchs that come off the first part are supplying part of the heart and receive enough supply. it's not restricted. once you get to beyond the narrowing, any tissue -- heart tissue, muscle downstream from that is going to be subject to a reduced supply. in this particular case, he had significant narrowing of all of his coronary arteries close to

the origin, which is consistent with all of his heart, unfortunately, being subject to reduced supply, the entire heart. >> is there a certain amount of narrowing that forensic pathologists consider to be enough to cause sudden death? >> the typical conventional number that forensic pathologists use is between 70% and 75% narrowing is a risk factor for sudden cardiac death. >> can you survive with greater than 75% narrowing? >> absolutely. i have seen many, many cases where it can be 90%, 95%. it depends where on the artery it is.

proximal narrowing is more dangerous than a distal narrowing. only part of the heart -- in this particular case, we know mr. floyd had 90% narrowing. he was walking around with 90% stenosis, beyond the 75%. that was not affecting him as part of his daily activities. when he was at rest, walking around, doing his normal daily activities, i know of no information that he was symptomatic or having any problems. yes, you can go beyond 75%. >> that's why cardiologists conclude you can survive with greater than 75%? >> yes. i think the difference is that medical examiners see people who died with 75%. cardiologists see people who are walking around with 90%. they see the live population. we see the dead population. we probably end up with

different standards based on, unfortunately, that's what we see. >> in terms of an autopsy finding, can you describe what necrosis is and whether that's necessary to diagnose a sudden cardiac death? >> it's something you can -- you have to visualize it microscopically. you have to look at the individual heart cell. it's a word which is heart cell. you can infer there may be necrosis at autopsy if you see bleeding into the heart itself. it is a microscopic diagnosis. it's not necessary for it to be

present for a sudden cardiac death. >> someone who has a sudden cardiac death may not have this? >> correct. >> why might that happen? why might someone not have that? >> again, the heart goes through a process of dying. it takes a while for a heart to die and to see the changes we can see under the microscope. we need to understand that that's why you can do heart transplants. somebody who has been injured or suffered some other can a at that time -- catastrophe, their heart can be removed, put on ice, flown across the country and put into another person without any damage to that heart. that process takes hours.

if the death is rapid, you will not see this. it's going to be somebody who has had symptoms and survived for a period of time so that that process can advance to the degree where we can see it under the microscope. >> okay. you have talked about sudden cardiac events. let's talk about the arrhythmia. can you describe what is called the conduction system of the heart? >> the conduction system of the heart is a very important part of the ordinarily contraction of our heart. we have two chambers which receive blood from the body. we have two muscular chambers that pump blood under high pressure to the body.

the way the heart works is it's a two chamber on each side. one side supplies the lungs and the other the body. the atria contract and push blood into the ventricles to fill them up. the ventricles contract to push blood to the body. they are very powerful. there's a valve in between to stop the blood flowing back. what you need is an ordinarily contraction process where the atria contract first followed by the ventricles. this is coordinated by the conduction system. we have in the heart what is known as the cardiac pacemaker. generic term. it's the little piece of modified heart muscle that actually has almost nerve-like function. >> does it have a name? >> it's a sinal atrial node.

it starts contracting. between it at the other node at the junction of the atria and ventricles, there's a bundle of modified heart muscles that conduct that down. then there are further modified heart muscles that go down to spread the impulse -- the electrical impulse to the heart to cause it to contract. >> what are those? >> that's the bundle of fibers. they all have medical terminology. it's modified heart muscle cells. what that does is it fires and the impulse is conducted down to the av node. at that time, the atria

contracts. the node fires, shortly after the atria. the heart contracts and sends the blood on its way. you have this ordinarily double beat to the heart. you can hear the valves opening and closing, atria and then the ventricles. that's the sound the doctor listens to. >> that's the blood pressure? >> the blood pressure is actually generated by the contraction of the ventricles. that's the essential up of the heart. >> what happens if this gets impaired? >> you don't have ordinarily contraction of the heart. if they fire at the wrong time, then if you had the atria and

ventricles moving at the same time, you would move no blood. the ventricles slam the valve short. you have no flow to fill the ventricles. >> is that an arrhythmia? >> that's an arrhythmia. there are different types that are documented. >> what can happen -- can sudden death happen as a result of an arrhythmia? >> absolutely. >> which artery supplies that pacemaker that you described? >> the sa node is supplied by a small branch that comes off the right coronary artery. >> did you review, again, the autopsy and observe findings relevant to mr. floyd's right coronary artery?

>> yes. unfortunately, that was the artery which showed the greatest degree of narrowing. >> which was how much? >> 90%. >> does that increase or that type of narrowing increase the risk for sudden death? >> yes. in that if and when the blood supply needs of the heart on the right side increase -- that's going to apply to the nerve, are not met, it will not function properly. you will end up with an arrhythmia of some sort. >> if it misfires there's no pacemaker? >> that is correct, yes. >> how does exertion come into the analysis?

>> exertion basically increases the demand for oxygen throughout the entire body. mostly because of the muscular activity. as we exercise, our heart rate and our breathing rate normally compensate to increase the oxygen that we're bringing into the body through the respiratory system and increase the amount of oxygenated blood being distributed to the body. the way that that increase of blood -- the way the body increases the blood supply is to increase the rate of the heart. we will go from our resting heart rate, which is between 60 and 100, we will push it up to 120, 140, 150, depending on the degree of exertion. beyond, it gets dangerous. >> essentially, the more exertion, the more oxygenated

blood is needed? >> yes. >> how do drugs like methamphetamine come into play as far as the -- in terms of the conduction system? >> methamphetamine is dangerous at several levels in this particular case. one, it has the ability to sensitize the heart to arrhythmia. it has been documented that people on methamphetamine have an increased risk of an arrhythmia. secondly, it increases the rate the heart beats. as a stimulant, it pushes the heart beat rate up. therefore, the heart is going to demand increased oxygen. the heart muscle itself. thirdly, it is a vasoconstrictor. it's a substance which causes

blood vessels, usually arteries, to narrow. it's physiologically important. it's important in certain circumstances, but can become dangerous in others. the way a vasoconstrictor works is to act on the muscular layer that's present in arteries. our arteries have multiple layers. there's a muscular layer in there. it causes that muscular layer to begin to contract. a little contraction, it's good. too much and it can slow downed blood beyond what is necessary. in certain circumstances, you can stop the blood by giving a vasoconstrictor substance. >> in this particular case, we have an enlarged heart. right? >> yes. >> we have a heart that has narrowed coronary arteries, right? >> yes.

based on your review of the video evidence, you observed a significant struggle between mr. floyd and the three officers? >> correct. >> methamphetamine on board, which is a vasoconstrictor? >> yes. >> have you or your colleagues ever certified a death due to the the the narrowing? >> yes. >> at these levels? >> anything above 75%, as i previously mentioned, meets the criteria for enough narrowing within the community of practicing forensic pathologists. >> have you ever performed an autopsy expecting one cause of death but finding another?

>> that's why we perform autopsies. it's a thorough investigation -- internal examination to identify anatomic deviations from normal. so, therefore, your preconceived notion -- i wouldn't say common example, but we see it every now and then would be a motor vehicle collision. somebody has multiple injuries. you look at them and go, okay, they have enough injury there to kill them. when you go in, you can see evidence that they had a stroke or a heart attack. that's what potentially caused them to lose control of their vehicle at the time and got the multiple injuries. then we are stuck with the issue, do we put heart attack under part one or the heart attack and/or the stroke-type findings under significant conditions? obviously, they were driving

their vehicle. it may have caused them to lose consciousness. these are just dilemmas we face as to where you put things on a death certificate. sometimes you are not right and you are not wrong. >> how about hypertensive cardiovascular disease? how does that relate to a cause of death? >> again, there are a number of sudden cardiac deaths that are related solely and exclusively to the increased size of the heart. those are the ones that -- since hypertensive disease is the most common cause of an enlarged heart, we will typically use that as the cause of death and say, hypertensive cardiovascular disease. >> have you ever certified a death due to hypertensive cardiovascular disease? >> yes, i have. multiple times.

>> you have diagnosed both hypertension and coronary artery disease as a cause of death in combination? >> yes. again, that is probably even more common because a significant proportion of the popular have hypertension. their hearts are enlarged. as you get older, you tend to lay down deposits of material in your arteries. there's often both present in many, many cases, unfortunately. >> again, in terms of hypertensive cardiovascular disease, we talked earlier about the struggle between mr. floyd and the officers getting into the squad car. how does that type of exertion play into hypertensive cardiovascular disease? >> it increases both with the hypertensive andage row

-- the more the person is stressed, the more the demand on the heart will increase. >> in terms of stress, how does that affect the heart? >> we have certain stress mechanisms built into, reflexes built into us. it's the flight and fight reflex is the common terminology you will see within the medical literature and also within the lay literature. this is a mechanism where if you are in a stressful situation, it prepares your body to be able to cope with the stressful situation. what happens generally is the sympathetic part of your nervous system begins to act. that causes secretion of adrenaline is one of the

examples and other substances part of that sympathetic nervous system. adrenaline causes your -- some of your blood vessels to constrict. it's another potential vasoconstrictor. the idea being you don't need to digest the food in your stomach, for instance, while you are in a very, very dangerous environment. it really pushes the blood to the organs that are more important, the heart, the lungs, the brain, your muscles. it shuts down the blood supply to your skin. it does all of those things. it also speeds up the heart to increase the cardiac output to maintain oxygenation of the brain, your muscles and other things so you can have an additional reserve to fight that

threat. >> the fight or flight kind of -- that you described, it increases adrenaline, right? it causes the heart to beat faster, agreed? >> yes and yes. >> and the adrenaline, how does that come into play? did you say that was a vasoconstrictor? >> it is a vasoconstrictor, yes. >> including the arteries? >> oh, yes. >> ultimately, what does that do potentially? >> it narrows the arteries. again, we have smooth muscle in the cardiac arteries. there's a potential of the adrenaline and the methamphetamine further narrowing those arteries in the heart as well as arteries

elsewhere in the body, restricting blood flow. >> in terms of that stress reaction -- i would like to craft this question carefully. the jury saw some evidence, which i know you reviewed as well, of an incident in 2019, about a year prior to mr. floyd's death, where mr. floyd was stopped by the police, was seen or believed and admitted to ingesting some controlled substances at that point and was subsequently seen by paramedics. do you recall that information in the information you reviewed, generally? >> i do. at the time that he was initially seen by paramedics, his blood pressure was taken. if i'm not mistaken, it was 216 over 160. what does that signify to you as far as this stress relation? >> high blood pressure like

that -- that's markedly elevated. could be due to his hypertension being out of control. this is much higher than i would expect. secondly, it could be part of the stress reaction where adrenaline is being secreted. it's pushing his heart rate up. that will increase your blood pressure. if adrenaline is secreted, it's causing vasoconstriction. there's more blood in the central vasculature. therefore, that can increase your blood pressure. there are multiple explanations for that. stress would be one of them. >> your honor, i believe that right now would be a good time for our midmorning break. >> we will take 20 minutes. let's reconvene at 11:10. >> good wednesday morning to

you. i'm jeff bennett. we have been watching testimony in the murder trial of derek chauvin. this is the second day the defense has called witnesses. we were just listening to dr. david foul he the former chief medical examiner in the state of maryland. he suggested may have contributed to his death and we should point out that dr. fowler himself is under a lawsuit trying to cover up the death of anton black an african-american man that died in police custody. before testimony started, the judge denied the defense's witness morries hall. let's go to a civil rights attorney and civil prosecutor. the defense is trying to under

cut the testimony from the prosecution's medical witnesses that said george floyd's death was linked to derek chauvin restraining him and kneeling on his neck. here is a key moment from this morning that we'll talk about on the other side. >> how did the heart and drugs contribute to the cause of death? >> they were significant. they contributed to mr. floyd having a sudden cardiac arrest in my opinion. that's how i'd read it. >> how is that different from the prosecution's witness. david fowler is saying mr. floyd suffered a sudden death during his restraint by derrick exact. the question at the end of the trial is what a substantial

contributing cause of george floyd's death. derek chauvin's knee on his neck that is obvious and the state's case or was it george floyd's underlying health conditions and drug use and the experts are saying exactly what the defense is indicating they'd say the whole time. basically, it was george floyd's fault. he had it coming and george floyd had nothing to do with it. >> and dr. fowler testified that drugs as we mentioned could have contributed to mr. floyd's death but also said that the size of george floyd's heart may have played a role. here is more of what he had to say on that front. >> when the heart or any of the muscle grows in size, its consumption of those vital components increases. so mr. floyd's heart would have twice the need of those nutrients. >> so how does that argument hold up and more to the point,

how will a jury digest that? because we heard from earlier testimony from the prosecution it was dr. andrew baker, the hennepin county medical examiner that performed the autopsy that said it was pressure and restraint and not the underlying conditions that caused george floyd's death. >> again, jeff, what you have to keep in mind here, it easy to miss the forest for the trees. a trial is like any other conversation. you pay close attention to what people say as soon as they get their first chance to talk. when the defense got its first chance to talk it went to the 2019 arrest video to portray george floyd as someone that uses drugs and has problems with the police. the person inclined to pay attention to that type of evidence is looking for something to latch on to as a result of derrick chauvin. this information gives them that. all they need to do is hear from a doctor saying it not really just the knee, it's something else because we start trying to

put it against the state's experts, i think it doesn't hold up. >> and nbc gabe gutierrez is outside the courthouse in minneapolis. gabe, what's your sense of the point that this witness was trying to make? >> reporter: hey, there, jeff. the key points he made or that george floyd died due to an enlarged heart and hypertension and not derek chauvin's knee on his neck. something else stuck out. he did bring up the toxicology and met amphetamine and he said there was exposure to vehicle exhaust, potentially carbon monoxide poisoning. that's an argument we haven't heard before but goes to what the defense is trying to do to especially say george floyd died from a variety of factors and not derek chauvin's knee on his neck, jeff? >> and david, a quick question to you. we should note as we did that

dr. fowler is currently being sued by the family of anton black in his role in that case. the only way the jury will know that is if the prosecution introduces it. do you think they know and do you think they should? >> i don't think they'll be able to introduce that, jeff. i would love it to come into evidence but they have to demonstrate somehow the lawsuit, whether or not the jury should rely on the testimony as an expert and i don't think they will get there. the bigger issue, you're pointing out is the fact that the defense experts are problematic. they're paid witnesses that will come in and say essentially whatever you need them to as long as you pay their fee. this current expert is being sued. the use of force expert is the same person that testified mcdonald's shooting in chicago was justified. i hope the jury will keep that in mind. the prosecution experts were not paid. they were just offering legitimate opinions. >> david henderson and gabe

gutierrez, my thanks to you both. that does it for me. we'll have much more coverage of the chauvin trial with andrea mitchell starts her show after a short break. andrea mitchell starts her show after a short break. ♪ you come and go ♪ ♪ karma-karma-karma- karma-karma chameleon ♪ ♪ you come and go ♪ ♪ you come and go-o-o ♪ ♪ loving would be easy if your colors were like my dreams ♪ ♪ red, gold -- ♪ [ tires screech ] [ crickets chirping ] for those who were born to ride there's progressive. with 24/7 roadside assistance. ♪ karma-karma-karma-karma-karma chameleon... ♪ because of the research that i've started to do on ancestry, with documents, with photographs, i get to define myself through the scores of people who lead to me. bring your family history to life like never before. get started for free at ancestry.com so you want to make the best burger ever? bring your family history to life like never before. then make it! that means cooking day and night until...

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for a second day starting with the medical examiner for witnesses. trying to rebut george floyd would not have died for the knee on his neck. he believed george floyd's drug use and health conditions were instrumental in his death. >> mr. floyd had a sudden cardiac arrhythmia due to his heart disease, you can write that down multiple different ways. during his restraint and subdual by the police or restraint by the police, he would have the toxicology, fentanyl and methamphetamine. there is exposure to a vehicle exhaust. so potentially carbon monoxide poisoning or