welcome back to our views in the united states and around the world. i am john king in washington and thank you for sharing a very consequential day with us. the defense making its case trying to layout an alternative cause of death for george floyd. prosecution witnesses testified again and again that chauvin's neck restraint deprived george floyd of oxygen and led directly to george floyd's demise, but today's expert says he sees something different. >> mr. floyd had a sudden

card cardiac arrhythmia due to his hypertensive heart disease, and can you write that down multiple ways, during his restraint or residual restraint by the police, and his significant contributary differences, he would have the toxicology, the fe fentanyl and methamphetamine, and there's exposure to a vehicle exhaust, so potentially carbon monoxide poisoning. >> let's discuss what we have heard today, cedric alexander,

and laura coates. it was not derek chauvin, it was something else, and this medical expert, a former medical examiner in the state of maryland, he is saying it's all of the above but it's not officer chauvin in his view. >> well, you know, as a prosecutor you look at this and how they have pretempted all of these things, and it's not the first time we are hearing about drug use and it's not the first time we are hearing about any of these conditions and the prosecution did a great job of preemtinge powerful expert testimony to counter what is being said right now, and he's saying during as opposed to saying the restraint actually caused, and words are really important to jurors, and there's an idea that is being planted, this seed, that he happened to die because of the underlying conditions during a police restraint. it's like an afterthought. it's not a winning strategy when

we know we have nine minutes of video and we have all the law enforcement police officers that have testified and we heard from a forensic pathologist and the medical examiner that did the autopsy and none had a dismissive tone that this happened during the restraint, but it happened because of the restraint. >> yeah, we will see what happens. this witness is still on the stand being examined by the lead defense counsel. as you listen, we have known all along eric nelson has tried to present an alternate theory of the case from the beginning and he just needs to win one or two of the jury while the prosecution has to win the entire jury. >> that may be true. at the end of the day, what is going to be more convincing in this case to go to jurors is

going to be what they have already heard, as laura has already indicated. they saw a presentation from the prosecution that clearly, clearly articulated the science down to the millisecond of what occurred with george floyd on may 25th. what we're seeing is a defense literally, a defense, and as of this morning looking at this expert witness that is on the stand now, looking at him, listening to him, a certificated and well respected physician, but at the same time it's not making the point about what it is that we all saw for those nine plus minutes. that's what is going to be the most important part of this case to me. you know, john, i sit here as a former police officer thinking about the number of physical fights that i have had over the

years in my career, where we had to take somebody to the ground or whatever the case may happen to be. but what a person states to you that is in your custody that you have handcuffed, they may be standing up erect, but even if they suggest they don't feel well, they feel hurt, you get them medical care. that's what is going to be so basic and fundamental here. it's great that we have the scientists in front of us, but you -- people are going to look at the basic fundamental elements of what happened and what they are looking at with their own eyes, and their eyes are telling them, their minds and hearts are telling them something very much is wrong here, and it's not matching up with what we learned the last two days. >> that's a critical point, laura, in the sense of any trial today, something happens in public and everybody has a cell phone and camera and not the case ten or so years ago, and

now in this case just the numbing sad nine minutes and 29 seconds the jury has seen, and as cedric just noted, we relive it when we see the entire video or just a piece of it, and that's what mr. nelson is trying to overcome. i want to listen to dr. fowler, and he's saying this would have happened anyway. listen to what he describes what he believe s is george floyd's heart condition. >> the size of the heart would be good evidence he had hypertension, and in this case methamphetamine which was present in mr. floyd has been associated with earlier onset of narrowing of the arteries. >> when you take it in the defense trying to raise some kind of doubt or alternative set of facts, what did you think of

the witness? >> well, first of all, the question never has been whether george floyd would die some day, it's not a trial to figure out if he was immortal, he is going to die some day, you and i will die some day, and everybody will die some day, and the question is why he died that day? and even with the narrowing of the art res, people go on to live. even the idea to suggest that the reason he died kau wcoincidy with the amount of force and you hear about the contortion, the equivalence of removing the left lung from his body, these images are sheared in the brained of the jurors, and subconsciously

with every single witness testifying we are remembering and comparing what they said not just against a prior witness, we are comparing it to what our eyes saw, our ears heard and our own observations through the video. this star witness is in the room every single time and is being compared and contrasted to try and assess the credibility of these witnesses, and until they address the obvious concessions and until they address we know common sensley has happened, they can introduce unicorns that fell out of the sky or allergens, but unless they talk about george floyd they won't move the needle. >> one of the things we have seen and one of the fast

fascinations of any trial, the prosecution tries to be nimble and we have talked about this in prior days where mr. nelson keeps saying reasonable officer, what would a reasonable officer do, and trying to plant that in the jurors mind, the call chauvin made was what any reasonable officer might have made. >> they are not doing anything and saying anything, so would a reasonable police officers would have been distracted? >> if a person is saying he can't breathe and continues to resist, albeit at a lower level, would a reasonable officer take that into consideration. >> we are in the 40s now in terms of witnesses, and part of it is also how the attorneys are trying to shape the key

audience, the jury. >> yes, so let's talk about reasonable just for a second, john. what's reasonable if we are sitting in a restaurant and somebody at the table next to us appears to be suffering a heart attack, we can reasonably assume that may be the case and render support and aid. if you're a police officer out on the street and you are managing the physical -- you are trying to manage a physical altercation and be mindful of this, you have two other partners, three other partners with you, you are not by yourself and a person tells you once they are subdued they are trying to breathe but you offer no medical help, it becomes reasonable that you do. nothing was reasonable in that case on may 25th from what we saw and from what we witnessed, so here again, i keep coming back to that point because at the end of all of this, that is

what's going to really matter, what touched people, what people have witnesses and seen over and over again and what has been explained to them, here again, down to the millisecond, that's what you call reason able expectation of a sworn police officer to provide reasonable aid, which they failed to do. >> common compassion, and every time we see it it stuns us. thank you for your insights. stay with us, and we are waiting for the trial. and another story is developing. officer potter killed and shot a 20-year-old, and tensions remain high in brooklyn center, ten miles south of where the derek chauvin trial is taking place. 30 people were arrested last night in that minneapolis suburb

in what police are calling a deadly mistake. as we wait for developments in that case, we will take you back to the courtroom, and this is dr. david fowler , a defense witness in the trial of derek chauvin. >> before the break we were discussing mr. floyd's heart and the contributions of mr. floyd's heart to his death. do you form to a reasonable opinion that you thought was the principle cause of mr. floyd's death? >> yes. >> what is that? >> cardiac arrhythmia due to heart disease during restraint. >> in terms of the other contributing factors to mr. floyd's death, as a part of your review did you make other considerations to things that may have contributed? >> yes, i did.

>> i would like to discuss with you carbon monoxide or c0, okay. >> you reviewed all of the d documents in the case? >> i did. >> did you pay attention to where mr. floyd's head was relevant to the squad car? >> yes, i did. >> which way was his face, nose and mouth facing? >> his face was facing towards the vehicle, towards the rear of the vehicle and directly towards the area where you would expect the tail pipe or tail pipes of a vehicle to be. >> let me just ask you, are you suggesting that mr. floyd died from carbon monoxide poisoning? >> absolutely, not, no. not a full carbon monoxide poisoning, no. >> all right. i would like to -- if the court

could publish and before the court does, the next slide has a screen shot from officer king's body-worn camera at 20:24:09. do you see that in front of you there? >> i do not at this time, no. how about now? >> yes. >> your honor, i have independently marked this single slide as exhibit 1058, and based upon discussions with counsel i move for its admission? >> any objection? >> no. >> exhibit 1058 is received. >> permission to publish. >> yes.

>> were you ever able to determine if the vehicle was running? >> there was evidence the vehicle was running. >> what would that consist of? >> what i observed was a -- i don't think this is working. what i observed -- >> objection, your honor, may we approach? >> you're watching a sidebar conversation during the testimony of the defense expert witness, dr. david fowler, and they are discussing an objection as they look at pictures of the crime scene, and laura coates as you watch this play out they are showing evidence from the crime scene and the defense expert witness was speaking and the prosecution objected. >> yeah, we're moving into the part where you are supposed to

be right now, where everybody is suspected, we have the background and now let's go to the facts in this case. that's what is most important here. all of the background information that helped to informs the jury, it informs but means nothing in order to assess what happened here away from the hypotheticals, and now we will talk about what actually happened and here's where i am most interested to see, john, if this medical experts going to be consistent and still offer alternate explanations for the cause of death given what we are seeing in the evidence in front of us and photos and the like. >> and cedric, if you are still with us, the key part of this just as it was when mr. nelson examined the prosecution's witnesses, the prosecution will get its chance and they have been effective so far. >> yeah, it will be a challenge for the prosecution, but from

their performance in terms of their preparation and what they have done up to this point i'm really looking forward to this cross-examination by the prosecution because they are going to challenge some of these myths that have been placed in front of us, so i'm looking forward to that. >> let's get back in the courtroom and see how this is resolved. >> dr. fowler, based on your general knowledge as a forensic pathologists and your personal experiences, what comes out of a car's exhaust? >> typically we see combustion coming out of the exhaust, and the major products will be water vapor, carbon dioxide, carbon monoxide and other small

particulate and minor gases that come out of the pipe. >> is carbon monoxide toxic? >> it's an extremely poison gas. >> how does it attach? >> it attached to the red blood cells and it attaches to those red blood cells more tightly than oxygen, so it competes for the same binding position on the hemia globin that oxygen does, and since it binds more firmly the oxygen can't displace it, and so as the percentage of carbon monoxide bound to your bloodstream slowly goes up you lose that portion of your oxygen-carrying capacity. so if you have a 10% carbon

monoxide saturation in your bloodstream, you lost 10% of your oxygen-carrying capacity. >> can that cause ultimately death? >> when you get to levels where in excess of 50, 60%, people typically, even young and healthy individuals will start to die. the issue is that people with significant heart disease and reduced capacity in the heart are going to be adversely affected earlier, and so there are certainly many examples in the literature of people dying in an environment when multiple people are exposed but one person dies and that seems like less than 20%, and others die at varying levels above that. and it's not universal that everybody will require to get to 60, 70, 80%. that's a young, healthy

individual. people with predisposing conditions who are vulnerable will die at much lower levels. >> in terms of the literature, are you familiar generally with the literature on carbon monoxide poisoning? >> yes. >> specifically are you familiar with the paper by demio and dana? >> yeah, there's -- >> this is cnn breaking news. >> we're going to take a break from the trial of derek chauvin to bring you other important breaking news. the former brooklyn officer kim potter is being charged in the killing of daunte wright. adrian brought us this live. what do we know? >> reporter: the washington county prosecutor has told cnn he will charge that officer, kim

potter, with second degree manslaughter. here in minnesota under the state statue, if somebody is convicted of second degree manslaughter the penalty is no more than ten years or a fine up to $20,000. for those of you who may just be tuning in, potter is the officer who was once here with the brooklyn center police department for 26 years. she fired the shot that ended the life of 20-year-old daunte wright. the former police chief here in brooklyn center told us she did not mean to fire that shot, she pulled her gun out instead of her taser. on that body cam video that was released soon after the incident occurred, you could hear the officer saying to mr. wright in the car, i'm going to tase you, i'm going to tase you, and then that was followed by taser, taser, taser. yelling taser, taser, taser is what officers are supposed to do before they deploy their taser.

but that did not happen. the family of daunte wright has said they have a hard time accepting what happened to their son on sunday was an accident. again, breaking news at this hour. the washington county attorney tells cnn he has filed second-degree manslaughter charges against potter. now, you may remember officer muhammad nor was also charged with second degree manslaughter and officer derek chauvin is on trial for the death of george floyd, and chauvin was charged with second degree manslaughter as well as second and third degree murder. john? >> adrian for us on the scene. let's get important insights now from laura coates, the former

attorney, and cedric. >> based on what we learn from the now attempted to be resigned chief, this idea of accidental, the notion is saying culpable negligent is going to be the standard. what does that mean? it means you are grossly negligent and reckless in your behavior. you created an unreasonable risk that would lead to death or bodily harm. you have the ten-year penalty as a ceiling of it, and on that notion this is very early on in the prosecution's case. it could be graduated to a higher charge. there's always a chance it could be reduced, and i don't see how it could be reduced but it could go up. and an officer in the past, missouri nor, he was charged,

and it's about whether they will be able to prove this officer created an unreasonable risk that she reached for believing it was a taser and accidentally reportedly got your gun, and is that reasonable for you to make that mistake and was it reasonable for the period of time that you held the service weapon in your arm not to know it was actually a taser. was it reasonable as well to fire and deploy the taser believing, of course, it was a taser and ultimately being a gun, and all of this goes under the same umbrella and it tracks what is happening with derek chauvin right now, because that's one of the charges he's facing. again, culpable negligent, john, is gross negligentance with recklessness, and that's going to be the key to solving this particular indictment and having a conviction. >> cedric, we talked about the issue of police training especially for veteran officers throughout the chauvin trial and now in this case former officer potter, she resigned yesterday, a 26 year veteran of the force.

these are dicey situations, but the argument given by the police chief, this was an accident. walk us through how they are trained to have the key distinction? >> certainly she has been around long enough and been since the inception of tasers when they were introduced years ago, and there's training you go through from weak side to strong side and your service weapon is always on your strong side. what occurred in this case is difficult and hard to understand for the common layperson, and certainly for many police officers it's hard to understand. can it happen? can it be an accident? maybe it can under certain stressful situations, but the question becomes is why was a service weapon pulled, and in addition to that why would it

have been necessary to even deploy a taser as well? so those are going to become the questions. i'm certainly going to be interested in what is going to -- how this case is going to evolve in listening to at some point the argument on the part of that officer and what was going through her mind, what was she experiencing? for somebody that is a 26 year veteran and for this to occur and however it occurs, you had somebody lose their life unnecessarily, and that becomes a real issue because there's a real gross negligence here that has taken place. they will have their day in court, but, again, a person lost their life. >> yeah, 20-year-old daunte wright is the person who lost his life in this episode. laura, walk through what you discussed because it's important how cases can evolve, and obviously because of the case in

the community and perhaps even because of the proximity to minneapolis and we know the chauvin is under way ten miles away. prosecutors clearly made a decision to act quickly and make clear they were going to bring charges, and as you note the investigation will continue and that can evolve. walk me through how that process works? >> well, you know, when you first become aware of an actual charge or arrest of somebody, prosecutors will routinely make a decision about the nature of the arrest, and whether they can satisfy the elements. it's not exhaustive, and we are only two days after the killing of daunte, and as you develop the case often times you might increase the particular charges. one way of doing so is if you learn additional information about the statements of the officer, about the state of mind, whether this was actually an accident. all we have to go by right now

is that the police chief who made the comment that he believed it was accidental, and we have the video where the officer says, oh, expletive, i shot him. that statement could be en interpreted that she made a mistake, or taser, taser, taser, that could undercut any statement that it's intentional. this is all going to be weighed, and it's an opportunity for defense counsel to talk about pleas. the longer and further you get into an investigation you get, the less chance of a favorable plea offer. i am not advocating for her to plea out, and it's a possibility in all cases, and one thing that needs to be talked about in terms of police accountability, what are the consequences? you have a ten-year sentence and

or a fine. it could be a lesser prison sentence if at all. what about things like a pension? most officers in jurisdictions may contemplate to resign or be fired and think about the consequences of, say, a conviction. minnesota is unique in many ways and one of the ways they are unique, they do not have a garnishment or a forfeiture of pensions for police officers even in the event of a conviction, and that might factor into why you choose to resign otherwise, and this might be -- it will come up later on, and it might be one of the reasons why the mayor is reluctant to accept the resignation of the police officer, and this is tracking in an eerie way the derek chauvin trial because jurors right now in that same county are trying to grapple with a charge of second degree machine slaughter, whether derek chauvin created an

unreasonable risk that caused the dead of george floyd, and the same question being asked of the now resigned officer potter and daunte wright. we're going back to the trial of derek chauvin. >> how does carbon monoxide come into play in terms of pulse exsim tur? >> it changes the blood to a color which the pulse thinks is oxygen. if you have somebody that has 50% of carbon monoxide, it will

read it's 95% oxygen. if it was put on mr. floyd's finger in the vehicle and again in the hospital, it does not give us any information allowing us to say he was or was not under the influence of some degree of carbon monoxide intoxication. >> how long does carbon monoxide typically stay in the bloodstream? >> it stays in the bloodstream if you want to treat a person and put them on 100% oxygen, the half life is about an hour to two hours. if you are exposed to ambient air, it takes longer to get rid of the carbon monoxide. >> in eventually removing that carbon monoxide from the bloodstream is a reversible process? >> it's not irreversible, it is reversible, so at some point it will disassociate. we do generate a smaller degree

of carbon monoxide as our metabolism, and it's less than 1%. so in small amounts, not an issue and it will disassociate and be blown off at some point as part of the normal metabolism. >> how much carbon monoxide is needed to be absorbed into the bloodstream to diminish the oxygen supply? >> well, for a young and healthy individual, you want to probably exceed the 60, 70, 80% range. that's what we typically see. however in individuals who have risk factors, that can be far, far less. >> what type of risk factors would you look for? >> so these are particularly -- the individuals particularly at risk would be with cardiovascular disease as we saw with mr. floyd, and people with

chronic obstructive lung disease would be at risk and other com comorbidities. >> what would you expect when somebody presents with those conditions? >> very difficult to predict because everybody is different. there are studies out there whereas little as 6% saturation of carbon monoxide in an individual who's exercising with heart disease will start causing ar aw areut mias. people started showing ekg changes and ventricular contractors at about 6%. it has a potential to affect

individuals at much lower levels than you would require for a young healthy individual. >> now in terms of findings at autopsy, are there certain things at autopsy that can determine the -- what the presence of carbon monoxide or certain observations the pathologist can make? >> typically carbon monoxide makes the blood appear -- it looks like it's cherry red in color, not the standard pink or darker red color we would see for deoxygenated blood. now, when it's 60% it stands out. when you are looking at levels that are 10%, 20%, it doesn't and is not easy to see.

a typical smoker, one pack a day, will have and can have 6%, two packs a day up to 12%. we just don't see that as forensic pathologists because there's so much background color from the normal blood that it's lost in that. i would expect a pathologists, when there's a substantial amount to spot it relatively easy, but i would not expect somebody to see the lower levels that can still be a factor. >> to do that you would need to test the blood? >> that would be the gold s standard, yes. >> so if you are not saying carbon monoxide caused mr. floyd's death, can you likewise eliminate it as a contributing factor? >> the only way to eliminate carbon monoxide as a contributing factor would be to

ensure that there was none in his blood or a very low level in his blood. so in mr. floyd, it robs him of an additional percentage of oxygen-carrying capacity, whether that be 5%, 10%, 15%, it takes away from the important factor of getting blood to his heart muscle. so this is just another potential insult, another brick in the wall, unfortunately for the circumstances here. >> utltimately the officers wer not affected by this? >> no, they were not. >> why could that be? >> they were two to three feet away and potentially, hopefully, they are much younger and hopefully don't have heart disease. so with every foot or more away, the amount of carbon monoxide in

that particular bubble is going to decrease. >> now, so we have discussed the heart and we have discussed carbon monoxide. did you eliminate certain causes of death as well? >> yes. >> specifically referring to asphyxia? >> correct. >> how would you describe the investigation of custodial deaths compared to other types of deaths? >> very complex and something that needs to be done very, very carefully. >> are there many variables to consider? >> absolutely there are a huge number of variables as we can see in the case of mr. floyd as well. >> in terms of this article here in your power point presentation, what is the significance of this? >> so this is an article that was put out i think about 1992

by dr. james luke and dr. donald ray. dr. donald ray was one of the first pathologists to theoryize that putting somebody in the prone position could be a factor and be considered. and later on he recanted that to a larger extent, but what he does say is that these are very difficult, complex cases, don't rush to judgment, make sure you have considered all of the potential issues that are at play in these particular cases, and only you can talk about a crystal ball in this particular case and the risk of underestimating the importance of common sense and the fact that there are no easy answers

in such cases. >> in your experience as a forensic pathologists, you have had an opportunity to perform a death investigation and autopsies of in-custody deaths? >> yes. >> in this particular case we have heard a lot about hypoxia. which organ is more sensitive to hypoxia? >> the brain is most sensitive, or rapidly sensitive to hypoxia. >> in your review of the materials did you have an opportunity to review some testimony of dr. baker in prior proceedings? >> yes. >> dr. baker in his testimony referenced some studies in terms of the affects of positional asphyxia. are you familiar with those studies? >> yes. >> did you take those studies into consideration as far as your analysis of this case? >> yes. that is the current state of the

science or the knowledge base with regard to this very difficult situation. >> so let's talk simply about the prone position. do people sometimes sleep in the prone position? >> yes. approximately 7% of the adult population sleep face down. >> in terms of medical examinations, treatments, are people kept in the prone position? >> in certain situations people are examined in the prone position. there are therapeutic maneuvers where people are deliberately placed in the prone position. one of the best examples right now is covid and patients will be put in the prone position, face down, and it improves their ability for oxygen exchange, not decreases it. so you know, the prone position by itself does not have -- or at

least there's no evidence right now that that is a significant condition. >> in terms of this particular case, of course, the prone position is, you know, not in a hospital setting, right, it's on the street, agreed? >> correct. >> and just generally speaking, if i -- if a person were to lay down on the street in the prone position with nothing on top of them, is that in and of itself inherently dangerous? >> the scientific studies basically have looked at the issue of the prone position with and without weight, and made a determination that there really is no significant impairment of the individuals respiratory function, and those particular studies were very carefully crafted -- >> let me just interrupt you for a second, doctor. can you just -- what is the kind of the leading study on weight applied to somebody in the prone

position? >> there are several, but the one that i've recently read -- not recently, but the one written by dr. mark krau and a couple other co-workers. >> is that paper here? >> yes, i believe that's the one, yes. >> positional compression of asphyxia, a brief review? >> yes. >> can you just explain this study, explain the setting of the study, et cetera? >> this is a review paper where he refers to various papers including his own work where no evidence of any kind of compressional asphyxia was found in individuals who were in the so-called hog-tie situation, which is prone with their hands handcuffed behind their backs. y additional restraints on their

ankles and the two tied together. that's the classic hog-tied position. and then up to 225 pounds, it was found no significant disturbance in their ability to exchange and breathe. the final conclusion was -- and there were 23 different studies out there that dr. baker referred to in his previous testimonies in the previous environment. in this paper the says it's an interesting hypothesis, unsupported by any experimental data. >> per saoupbt to the court's order you were permitted to review the testimony or watch the testimony of other expert witnesses in this case, correct? >> yes. >> did you do so? >> some of them. not all of them. >> did you hear criticism of

this paper? >> yes, i did. >> do you think that the study was flawed based on its methodology? >> the study was asking one specific question, is the prone position dangerous? when you craft an experimental process to look at a particular process, in this particular case it was the prone, you want to eliminate all other variables. you want to eliminate fear. you want to eliminate exertion. you want to eliminate environmental conditions other and focus entirely on that one entity. so agree that what is happening in this particular situation, they didn't use people who had heart disease. they used young healthy

volunteers. the surface they were lying on was not asphalt, it was a hard flow with a thin gym mat on it, and the individuals were not in fear of their life, and not a high saw kraetion of adrenaline. now you can go back and look at the other issues if you want to at some stage. >> now, in terms of the study by putting weight on the back, how did that work? >> so they were using bags of weight, sacks, and they continued to place them over the thorax, and even distributed across the chest and the area

where your lungs are, and it puts pressure on the diaphragm and they did not find any significant impact. >> you have ever seen an image of, like, a teen -- a baseball team winning the world series? >> you mean a human pyramid? >> yes. >> is that kind of the analysis or analogy they bring? >> yes. >> kind of -- lots of people piled up on top and somebody has got to be at the bottom, right? >> correct. >> in terms of the studies, and you talked about this particular paper, and that was a review of other studies, right? >> yes, and other work, yes. >> there were 23, i believe you said? >> that was the testimony that

dr. baker stated in the previous legal proceeding. >> so some of the other studies that they reviewed here? >> yes, it's a short list, not all of them. just illustrative of the developing information, and really this has gathered a lot of steam over the last couple of years, so prior to many of the studies, the wisdom of the position is dangerous was still accepted, as you can see from 2013, 2014, people are really beginning to look at this with a critical eye, and really adding to the body of knowledge within the medical of sciences and beginning to challenge some of these theories.

>> in terms of, again, just the research, the criticism offered by previous experts was that it wasn't real world, where some of these studies looking at real-world situations. >> correct. the real world ones are the two papers by dr. hall are the ones that really stand out, and the paper where she took a city of 1.1 million police restraints, and it was a city of 1.1 million residents and there were 296 cases where there was a forceful restraint, and the only death they found in that particular case was a person not in the prone position and they evaluated prone versus non-prone and statistically found no difference.

it is a small study. so they did a bigger study where they took four cities and looked at 5,000 force incidents, and their final conclusion was that their data supported the data of the studies done in the controlled environment, and that it has no physine. >> can you just describe for the jury this study and others and the impact of an officer's weight being a factor in the analysis of prone position and positional asphyxia?

>> well, basically the conclusion was it doesn't matter how much the officer weighs, 140, 150, 200 pounds. it doesn't make a huge difference to the outcome. what he did say is that with a double knee restpraraint, physically, two knees, it has a -- these are not testing res p respiration, and so how much weight are they transferring. with a single knee it didn't matter what weight the individual was. with a double knee, up to 23% of the body weight to be transferred to the dummy. >> up to how much? >> 23%. so they were not looking -- when you see it, it has a modest influence, and it has a modest

influence on the weight transferred, not the aspiration activity. >> do you know based on the review of individuals were you able to ascertain officer chauvin's weight? >> i was informed. yes, i have seen that weight. >> what is that? >> 140 pounds is what i was told. >> also in reviewing the videos, you see that he has two feet on the ground with the exception of one small moment? >> yes, that was what i did actually see in the video. >> so what portion of mr. chauvin's weight was transferred on to mr. floyd's body? >> he's using a single knee technique and his other knee through a great majority is on the left chest wall, and even if he applied both knees, which he

would have transferred 23 p% of his body weight, and for a 140-pound person, that would be between 30, 35 pounds. >> less than the 225 pounds from the laboratory experiment? >> yes. >> so in terms of, you know -- let me ask you this first. in terms of the placement of officer chauvin's -- excuse me, knee on mr. floyd, and is it your opinion mr. chauvin's knee impacted the structures of mr. floyd? >> no, none of the vital

structures would appear where the knee was in any of the photos. >> in terms of your death investigations, you reviewed the autopsy photographs and things of that nature, correct? >> yes. >> generally speaking, do signs of injury play into your analysis as to the cause of death? >> yes. >> how so? >> well, you make an observation of such in this particular case of a knee providing force to a particular part of the body, and then you go and you look at the same part of the body to see whether or not you can find corroborating evidence within the body itself, either an abrasion to the skin, subcutaneous hemorrhage, hemorrhage into the muscles or other injuries that may be caused by the knee. >> what injuries did you observe

in the photographs of mr. floyd? >> all of his injuries were in areas where the knee was not. in other words, they were on the front of his body, his face, his -- places where he was restrained, but there was absolutely no evidence of any injury on the skin to the subcutaneous issue or the structures of the back or neck. >> were there any broken bones, spinal injuries or anything of that nature? >> there were no broken bones documented. i did not see a description of the spinal cord in the autopsy report, but given that there was really no external evidence of the area and the muscles around the spinel column, i would be surprised if there was a spinal cord injury in this particular case. >> so you referenced the back of

mr. floyd. did you see any bruising to the skin? >> >> i did not see brucising o abrasion to the skin. >> did you see any bledding in the subcutaneous tissues of the neck and back? >> none in the photos nor was it documented in the autopsy. >> how about the muscles? >> the same. >> so in the absence of the injuries, how does that speak to the cause muchof death? >> it speaks to -- >> can you help us to understand how the knee relates to questions of injury and force? >> the two structures that would be of concern in this particular case, one would be the actual knee itself and the other would be the tibia.

this diagram shows this object right here. the chinbone. if you remove that particular circle that i just put in, you can see that the tibia has a relatively defined front edge right over here. you can feel it on yourself. it's a nice ridge all the way down, which is actually quite prominent and hard. it's right underneath the skin. so that allows an unforgiving service such as the chinbone to be placed on soft tissues that are vulnerable and cause some degree of injury to that area. that's the chinbone, and the

knee is not that much different. the knee is somewhat -- you have the patella and the ends of the femur and the ends of the tibia just below, all of which are bony and right under the skin and they can direct the amount of force. if you put a substantial -- 30, 40, 50 pounds worth of force and focus with your knee of somebody, my experience is a intra muscular damage is very, very high. >> you didn't see that? >> it's not documented. in strangulation and other situations where knees have been

used, yes. >> do you typically see marks in those cases? >> in manual strangulation, often you will see hemorrhaging into the muscles of the neck, and in cases where the knee has been used on the back, and we often see a bruise consistent and many times we have matched it to video cam footage of where we see a knee being placed, yes. >> including just fingerprints -- finger marks, i suppose? >> yeah, just the pressure from somebody's fingers is enough to cause muscle hemorrhage in a manual strangulation case. we're not talking about a person putting weight on somebody but just somebody squeezing the neck. >> when you look at this case and you see the knee is involved and the chinbone is involved, would you expect to see a greater likelihood of bruising

from just the fingers? >> objection, speculation. >> overruled. >> can you repeat the question? >> in this particular case where the knee is involved and there are allegations of force being used to subdue mr. floyd, would you expect the chinbone to have a greater likelihood to produce bruising? >> than fingers, yes. >> is there any objective findings in the autopsy showing pressure placed on the back? >> no. >> again, we have talked about hypoxia -- we can take this down now, judge. we have talked about hypoxia. what are the affects of hypoxia that you would expect to see if that were present? >> so there are some observable

symptoms when somebody becomes hypoxic. is that what you are asking? >> yes. >> what are those? >> people start to get confused, disoriented. they may have visual changes, a gray curtain coming down, and there are visual abnormalities people describe and complain of, and they have difficulty speaking. what is happening is your brain is getting short of oxygen, so you are getting decreased function of your brain and it's going to mimic intoxication by other sources. >> did mr. floyd in your review complain of those changes? >> no, he complained of