good afternoon, i'm katy tur. a critical shift in day nine of the derek chauvin murder trial in minneapolis. after days of focus on the use of force, the prosecution is now zeroing in on what caused george floyd's death. riveting testimony from dr. martin tobin, an expert pull -- pulmonologist, who wrote the

bible of breathing. dr. tobin says george floyd died of a low level of oxygen. he said he watched videos of floyd on the ground hundreds of times, and he came prepared with a 3-d animation to illustrate what happens. see it right there. the doctor at one point addressed the jury directly, demonstrating on his own neck where the air was cut off. i should warn you, some of his testimony is pretty difficult to hear. >> did you consider where mr. chauvin's left knee was during the encounter? >> yes. for officer chauvin's left knee is virtually on the neck for the vast majority of the time. >> and when you say "vast majority," are you able to be more specific? >> more than 90% of the time, in my calculation.

they were forced up against his chest, up tight, forcing it high up. you have to keep in mind, the opposite side of this is the street. so he was being squashed between the two sides. basically, on the left side of his lung, it was almost like a surgical humanectomy. it was almost the effect of a surgeon going in and removing the lung. you can see he's against the tire. to most people this doesn't look terribly significant. but to a physiologist, this is extraordinarily significant, because this tells you he has used up his resorts r sources and he is now literally trying to breathe with his fingers and knuckles. once somebody stops breathing, what will be the rate of decline in the level of oxygen, how long it will take to reach zero.

we see that he reaches a level of zero oxygen at 25: 24:41. he reaches a level of trying to breathe from the rest of his body. >> reaching the levels of trying to breathe through his fingers. the movement of george floyd's leg in this video shows he was having a seizure due to a brain injury from that lack of oxygen, then he lost consciousness. and eventually there was no oxygen left in his body. basically, he was dead, and yet derek chauvin's knee remained on his neck for three more minutes. dr. tobin also says george floyd's health issues did not cause his death, nor did the fentanyl in his body cause the

lack of oxygen. in his words, a perfectly healthy person subjected to what george floyd was subjected to would have died from this as well. and perhaps the most wrenching moment, dr. tobin analyzed close-up video of floyd's face with chauvin's knee on his neck. >> you can see his eyes, he's conscious, and then you see that he isn't. that's the moment the life goes out of his body. >> the moment the life goes out of him. that is just heartbreaking to hear. joining me now is news correspondent gabe gutierrez who is in minneapolis, expert pulmonologist dr. gupta.

gabe, i want to start with you. how was the jury reacting? >> reporter: hi there, katy. this is supposed to be among the driest, most technical testimony we've seen so far, so you wonder how might the jury react to this. we're getting initial reactions from our four reporters inside the courtroom, and according to the core report, the jury was very attentive. they're taking notes, obviously impacted by this testimony, and you could see it from the doctor's testimony. he was engaging with the jurors, he was making eye contact with them. it certainly comes from his experience, as he says, testifying in dozens of trials, about 50, he says. so, katy, you mentioned a lot of the highlights in your setup, but what really struck me was the moment when the doctor was discussing not just the knee on george floyd's neck, but also the handcuffs behind him, how that impacted his breathing. it's going to be very tough for

the defense to refute some of that based on any cross examination. we're expecting that after the break, but katy, it was just incredible to hear this world-renowned leader in his field really picking apart the defense's argument point by point. this all sets up the county medical examiner who is supposed to testify tomorrow. his controversial autopsy report did not mention asphyxia, and it has been used in the argument that floyd had large amounts of fentanyl in his system, and you hear the doctor there basically picking apart that issue, katy. >> dr. gupta, you're also pretty preeminent in the field of pulmonology. we're really lucky to have you to talk about covid, but having you to talk about this, i want to know, from your expertise, what did you make of this testimony? >> good afternoon, katy.

it's really difficult to listen to, but everything dr. tobin said, he's an icon in our field, was correct. let me key in on a few things for your audience. one, this notion that fentanyl played any role. for those who know how fentanyl works, basically this will cause somebody to be sleeping pretty quickly. it will cause them to have their respiratory rate decline. normally, katy, you and i are breathing about 10 to 12 breaths a minute. fentanyl will cause respiratory rates to climb maybe 4 to 6 breaths a minute. dr. tobin properly noted that mr. floyd was breathing about 20 breaths per minute. he was at a higher than normal breathing rate trying to get more breaths in. by the way, that does fight the argument that fentanyl played any role. i thought the movement he emphasized that was important

was the contorsions of the hip that george floyd was trying to free up. his right chest was the only way he could get a breath in. he was trying to get a breath by opening up his right chest, because as dr. tobin said, his left lung was virtually nonexistent because it was already smashed into the street. basically we had a situation where his lung was being strang -- strangulated, his rib cage was also useless, which then resulted in cardiac arrest. >> the witnesses said george floyd's whole body weight was on george floyd's body, not just the neck, but the back. he also talked in great detail,

dr. gupta, about the compression of the hands on the base of the back by derek chauvin and one of the other officers. what does it mean when the person's entire body weight is not just on your neck but on your back? >> katy, the only way to get enough oxygen into your blood through your lungs is if you can take an effective breath. that's you and me being able to lift our rib cage. mr. floyd was unable to do that because he had a very heavy person leaning his entire body weight on him. i thought it was important to say that the boots of derek chauvin was not actually hitting the ground, it was -- his entire body was focused on his chest and on his neck, meaning he couldn't elevate the rib cage. having, actually, the hands handcuffed behind his back, mr. floyd's back, prevented him from using his appendages from lifting up, to potentially lift his rib cage even a little bit

to get a small breath in. but the combination of the strangulation of the windpipe and the elevation of the rib cage rendered him useless getting breath for just a few minutes. oxygen level is about 70% less for about four minutes. that's when you'll start seeing seizurelike activity, a flickering of the eyelids, and that's exactly what happened. >> joyce vance, from a legal standpoint in this case, how does a jury take in an expert like dr. tobin? >> this evidence, this testimony is effective precisely because it's so painful to listen to. it almost puts the jury into the position of experiencing the pain that was inflicted on george floyd, it personalizes

the experience in a way that little else can do. and there is something else important going on in this testimony. while psychologically it's devastating to the defense, it also lines up very neatly with what the jury has already heard from police, from everyone that they've heard from, from police employees in minnesota to the excessive force experts yesterday who talk about the risk of positional asphyxia and who say being prone, being cuffed creates a risk of asphyxia when you add pressure on the body, whether it's on the neck, on the shoulderblade, it increases that risk and now we have a medical expert who says, yes, this is why police train the way they do, in effect. this is what the risks are, and this is what caused george floyd's death. it's a very good piece of testimony for the prosecution, but the defense still gets to cross-examine. >> they'll do, and they'll do so

at 2:30 eastern time in just a few minutes. they'll get their chance. joyce, one of the things that really stuck out to me was when dr. tobin asked the jury to touch their own neck and feel where their own spinal cord was, touch their own throat, feel where they do their breathing. i wonder, when you have somebody asking the jury to physically get involved, to physically feel what a victim felt in the moment, how effective can that be? can it ever backfire? >> you know, everything can backfire in a trial setting. but this worked. it worked really well. there was a sidebar during this testimony, and i suspect that the defense objected to it. they didn't want to see this personalization for the jury. if there is a conviction, the defense will argue on appeal that this was an error for the

judge to permit the expert witness to do that, but add migts evidence is largely within the judge's discretion, and here this paid off for the prosecution. >> there was that, there was george floyd's boot not on the ground, his body weight -- or derek chauvin's body weight on george floyd, there was the fact that the doctor testified that the last breath went out of him and yet derek chauvin was still on him for over 3 minutes more. and then after officers found no pulse in george floyd, they were still on top of him and remained there for 2 minutes and 44 seconds. a lot of really damning stuff in that testimony right there. gabe, gutierrez, dr. vin gupta and joyce vance, thank you very much. joyce, don't go anywhere. you're sticking with us for the hour. the trial is expected to resume soon. when testimony gets underway, we'll go back inside that courtroom. in the meantime, joe biden

developed a series of actions on gun violence based on what happened in just the last month alone. in march, within 15 days, three high-profile mass shootings in georgia, colorado and california. and then just yesterday another one in south carolina where a gunman killed a grandfather, a grandmother, their two children and another man at a private home in rock hill. the president's executive orders direct the justice department to issue a ruling on so-called ghost guns, on traceable weapons that can be made at home from parts purchased on the internet. the president says he wants those drug kits to be treated as firearms. he also ordered the justice department to propose a rule on stabilizing braces, and to

public "red flag" legislation for states. today the president said enough is enough. he called gun violence an epidemic, and said something must be done. >> violence in this country is an epidemic. let me say it again. gun violence in this country is an epidemic, and it's an international embarrassment. our flag was still flying at half staff for the victims of the horrific murder of eight primarily asian-american people in georgia. ten more lives were taken in a mass murder in colorado. you probably didn't hear, but between those two incidents, less than one week apart, there were more than 850 additional shootings. >> joining me now is "new york times" chief white house correspondent peter baker and the president of brady, chris

brown. chris, i want to start with you on this. executive orders not as effective as legislation, but i'm wondering on your take of what the president did today. what is it? >> we're really pleased with the action that he's taken. he also, katy, called on congress to act, so it's not a substitute for the things they need to do to expand the brady background check system. but the kinds of changes he's asking merrick garland to make are ones that we had recommended at brady over the last year, looking at the kinds of things that atf can do in its own authority to better regulate ghost guns. those are proliferating all across the country to issue this gun trafficking report. that's really important, katy, that's data that is not public. the nra has fought such a report for the last two decades. that's the last time atf produced this. that's pivotal, because a huge number of guns that are flooding our communities come from a relatively small number of dealers. we need help pinpointing those

and stopping the flow of sales. this intervention is a big investment in proven strategies that work that have been really underfunded. so we're pleased with the comprehensive nature of these proposals and with the recommendation of the nomination of david chipman, who is a true champion for gun violence prevention, and someone who worked at the atf for 25 years, so certainly knows the agency. >> chris, what about the messaging on this? there are a lot of people out there who will look at congress, will look at the government and say, hey, listen, if you couldn't have gotten it done after sandy hook, after all those kindergartners were killed, how can you do it now? what's making the difference now? how is joe biden doing in terms of messaging, trying to convince people that it's not about taking their guns away, it's not about violating the second amendment, it's about making sure that innocent people aren't

killed by crazy people who get their hands on a gun? >> katy, that's exactly the point that he made today. we were really pleased that he called it what it is. this is a public health epidemic. and he also noted that none of these strategies in any way violate anyone's second amendment rights. he noted, and this was said on the campaign trail by someone who is now his secretary of transportation, that the second amendment doesn't have to be interpreted as a death sentence to our fellow americans. these kinds of efforts have broad support among gun owners, non-gun owners, all americans because we're all sick and tired of the epidemic of gun violence. i think importantly he's noting that these are public health solutions and building the case, not just for legislative change, he's saying that must happen, but also for funding and for his cabinet, his agencies, to look at this comprehensively as the

kind of health epidemic that it is. >> part of the reason it hasn't happened so far are because of single issue voters who only vote on issues of their guns, and all the money that is poured into specific candidates, specific lawmakers, to not change anything. >> that's right. if you do polls on ideas that this president has put forward, either the executive orders he put forward today or legislative ideas he's talked about, he shows a lot of broad support across party lines, even with a lot of gun owners according to surveys of the past. but the gun rights lobby has made very, very good use out of the fear of the slippery slope. in other words, if you allow them to do background checks or expand background checks, or you were to ban magazines with more than ten rounds in it, that's the beginning of a much broader effort to take away our guns. that has worked in many

districts where, you know, that idealogy, that philosophy is more prominent. it's been successful over the years. it is not the same thing it once was, but lawmakers believe they've learned lessons in the past which means they can lose on an issue even if polls show broader support for the kind of measure the president is talking about. >> so is there any movement right now, anything different in this moment, peter baker, that would mean there is more of a chance for this sort of legislation? >> it didn't seem like it. you still hear people talking about it, you hear pat toomey, the republican senator from pennsylvania who tried to come up with background check legislation with joe manchin if there was something they could get republican support for. it doesn't seem the dynamics have shifted in capitol hill.

the senate put down that proposal in 2015, and of course the house is pretty tight, too. i don't think the dynamics have shifted too much on capitol hill. at least nothing has shown that they have so far. >> peter baker, chris brown, thank you guys very much. we expect the murder trial of derek chauvin to reconvene in just a few moments. when it does, we'll go right back into that courtroom. first up, though, 1 in 4 million americans have gotten the covid-19 vaccine. so why is it that we keep hearing that we still may be in for a surge? and amazon is trying to form a union. it's a decision that could impact amazon employees all across the nation. that could impact amazon employees all across the nation.

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225 million doses are being distributed daily, but despite that good news, it seems to be transitioning in the wrong direction. across country, new infections and hospitalizations are climbing, particularly among younger people. the latest epicenter is michigan

where fema is sending its own teams to help hurry up vaccinations as new cases and hospitalizations have more than doubled over the last two weeks. with me now is dr. jha. he is the dean at the school of public health. dr. jha, it's good to see you. i think there is people who say younger people do better with this, so maybe the spike in infections are maybe not as big of a deal as some of our public health experts might suggest. >> katy, thank you for having me on. first and foremost, absolutely true that it is really good stuff that we're not seeing a massive surge of hospitalizations and deaths from older americans. we should take that as terrific progress. the problem here is that there is still a lot of young people who are vulnerable, a lot of them are infected, and a good chunk of them are getting

hospitalized and starting to die, which i think is tragic, especially since we're so close to being able to vaccinate all adults in the united states. therefore, this surge of infections and hospitalizations in young people, i don't think, should be taken lightly. >> we're about a week and a half away from april 19th when everyone in the united states over the age of 16 should be able to get a vaccine. the federal government not sending more vaccine supply as of now to michigan. what do you think of that? >> look accident here's what's going on across the country. there are probably about a half a dozen states where we've seen vaccinations really starting to slow, and the gap between how many vaccines they're getting and how many they're administering is widening, meaning more vaccines are starting to sit on shelves, places like georgia and alabama and arkansas. my take right now is michigan needs more vaccines. i love the move by fema, i think

that's really good. i want the federal government to substantially ramp up vaccine distribution to michigan. we should get those into people's arms. it's going to make a difference. we've got to be able to do this when there are surges to try to help states out. >> there's still quite a bit of hesitancy out there particularly among republican men to get the vaccine. how do you convince people who don't want it, don't trust it, don't really need it, to get the vaccine? and i'm not saying you, dr. jha, because i don't think it's up to public health experts, but if you're talking to a family member who is talking to another family member who doesn't want to get it, or a local doctor talking to their patients, what do you suggest? >> this is going to be about trusted voices. this is about people who are trusted by the folks you're trying to influence. so if you're talking about, let's say, evangelicals where you see a lot of hesitation,

it's going to be evangelical leaders who are really important to that messaging. if you think about republican men, it will be republican leaders like donald trump who i think has a lot of sway and influence. i keep hoping one of these days he will cut a commercial himself just talking about the importance of these vaccines since his administration oversaw so much of the production of these vaccines. but it's really about engaging the trusted voices and having them speak up about this. obviously, we all need to add our voices to that, but it will take all of us to push this forward, not a small number. >> we can't get to herd immunity unless the vast majority of us get this vaccine. dr. ashish jha, thank you for joining us, as always. the vote count will begin next hour in alabama as amazon workers will decide whether to form a union. the facility would become amazon's first unionized

warehouse. this vote could have implications for amazon facilities across the country. amazon is already challenging hundreds out of the thousands of ballots cast. we're keeping an eye on that. and still ahead, how today's testimony in the murder trial of derek chauvin could serve as a precursor for tomorrow's testimony. that is when the medical examiner who did the autopsy on george floyd will take the stand. l take the stand. i don't know. i think they look good, man. mm, smooth. uh, they are a little tight. like, too tight? might just need to break 'em in a little bit. you don't want 'em too loose. for those who were born to ride there's progressive. with 24/7 roadside assistance. -okay. think i'm gonna wear these home. -excellent choice. this is the planning effect. as carla thinks about retirement, she'll wonder, "what if i could retire sooner?" and so she'll get some advice from fidelity,

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in just a few moments, we will turn back to the minneapolis courtroom for the trial of police officer derek chauvin. on day nine of this trial we've entered the medical portion of the prosecution's case. earlier today we heard from a pulmonologist, dr. mark tobin, who said george floyd died from a lack of oxygen. he also told the jury that the cause of death was from the

restraint of air posed by derek chauvin. also joining us is minnesota public radio reporter brant williams and also joyce vance. brant, it's good to have you. you were there for jury selection. obviously the defense only needs one single juror to decide they see there is reasonable doubt that george floyd killed -- or derek chauvin killed george floyd. do you have a sense of who the prosecution or whether the prosecution might be targeting one juror in particular? >> no sense of that, but i was in the courtroom yesterday when the jurors were subjected to some mundane evidence. their attention started to wane a little bit, and i think that's something they will have to --

>> brant, as you can hear, we've just gone back into the trial, and the testimony will resume with dr. tobin. i believe he is being cross-examined now by the defense. >> i want to review a few things with you, sir. i don't think we'll take too long. you were ultimately approached by the state of minnesota to assist in the review of the medical issues in this case, correct? >> correct. >> and you have volunteered to do this work at no cost, correct? >> correct. >> you're not normally involved in criminal cases of this nature, correct? >> correct. >> this is the first time you've ever been involved in a criminal case, correct? >> correct. >> and it was for that reason that you decided not to charge a fee, correct? >> correct. >> when you are in other cases, what type of fee do you normally charge? >> i charge per hour. >> what's your hourly rate? >> my hourly rate is 500 an

hour. >> but you agreed to waive your hourly rate for this case, correct? >> yes. >> you felt it was an important case, right? >> yes. >> in preparation for your testimony today, you met with the state numerous times, correct? >> correct. >> you have had the opportunity to review all of the medical information that was obtained in this case, correct? >> yes. >> that would include mr. floyd's previous medical history, correct? >> correct. >> the autopsy and attending toxicology reports that were prepared in this case? >> yes. >> as well as some investigative materials, police reports, things of that nature, correct? >> correct. >> just correct me if i'm wrong, but you're not a pathologist, correct? >> correct, i am not a pathologist. >> your specialty is in pulmonology, critical care, things of that nature? >> correct. >> and you also have an interest and an impressive resume

relevant to applied physiology as well? >> correct. >> and you've been honored quite extensively for your work in that regard, right? >> correct. >> you're not a minneapolis police officer? >> correct. >> it's fair to say that the training that is provided by the minneapolis police department in terms of medical care comes nowhere close to your level of expertise? >> correct. >> you understand that minneapolis police officers are not even emts? >> correct. >> they have a basic life saving certificate dealing with gunshots, chest seals, tourniquets and cpr, right? >> yes. >> you've also had the opportunity to review a lot of the body camera footage, correct? >> yes. >> you've done -- i think you testified that you've watched these videos hundreds of times. >> correct. >> and you've watched them all from all different angles, correct? >> correct. >> and you've had the luxury of slowing things down, putting it

into slow motion, still framing various times, correct? >> correct. >> so your analysis of this case comes after hundreds, if not thousands, of hours of time spent looking at this information? >> i don't know the total amount of times that i've spent, but it's substantial. >> so then you ultimately, based on the review of all of that, you prepared a report, correct? >> correct. >> and you provided that to the state of minnesota in late january of this year, right? >> january 27, yeah. >> and after that you had numerous meetings with the prosecution team in this case? >> by phone or by zoom, yeah. >> including january 30th of this year? >> i don't know the dates, but, i mean, that sounds correct. >> so if i were to tell you the dates were january 30th, march 3rd, march 9th, march 17th, march 21st, april 1st and april

7th, you would not have any reason to dispute me? >> i have no reason to dispute that. >> you understand that notes are made of those meetings and provided to the defense in this case, correct? >> i understand that. >> you've also been able to spend a substantial period of time preparing the exhibits that the jury was able to see earlier today, right? >> correct. >> and those were all prepared by you or someone within your team, correct. >> they were prepared by me, yes. >> you provided those to the prosecution in advance of today's testimony? >> correct. >> and you understand those were provided to me last night? >> i have no idea when. >> so you've had a lot of time to prepare both yourself as well as the prosecution team in connection with this case. fair to say? >> correct. >> now, you talked quite a bit about physics in your direct testimony. agreed? >> yes. >> and you would agree that physics or the application of

physical forces is a constantly changing set of circumstances? >> i didn't catch what you said. >> sure. you would agree with me, would you not, that when you look at the concepts of physics, these things are constantly changing, right? >> all the time it's constantly changing. >> constantly. in milliseconds or nanoseconds, right? >> yes. >> so if i put this much weight or that much weight, all the changes in variations will change second to second, millisecond to millisecond and nanosecond to nanosecond, right? >> sure. >> my lungs breathe, my brain is sending millions of signals to my body at all times. >> correct. >> faster than the speed of light, correct? >> correct. >> millions of signals every

nanosecond, right? >> yes. >> i think in your report you even kind of discuss that when you're talking about these instances, when you're talking about the physics or the biology, what you're really talking about is a single kind of nanosecond, that all of these processes are working in concert at all times, right? >> the way we talked about this is a mean value. it all comes down to one instant. >> you've taken this case and you've literally boiled it down to a nanosecond? >> i wouldn't say that, no. in my report, you see it's sequential. there is a whole chronology. i begin from the time the knee is placed on the neck and then all the time until what's happening in hennepin county e.r. >> so your report talks about the sequential nature of things, but when we talk about the

biology and the physics of this case, these things are working simultaneously, contemporaneously all together, right? >> that's correct. >> in an incredibly rapid fashion. >> yes. >> and you would agree with me that as this incident was occurring, there was nobody measuring the units of force that were placed in any particular position of any particular person at any particular moment, right? >> there was nobody there measuring the amount of time, i agree with that. but they're all calculable. >> understood. when you calculate them, what you have to do is you have to boil them down into what you would call the mean or the average, right? >> correct. >> so whenever we look at the concept of an average, there are

things that are happening moments before, moments after, right? >> yes. >> and forces will increase or decrease relative to the nanosecond of time, agreed? >> correct. and ultimately when we talk about kind of the biology of things, a pathologist tries to look at the intersection of all the things that occur in a particular death investigation, correct? >> i mean, they're not looking at anything to do with physiology. >> understood. but they're also looking at how other factors may contribute to the death of an individual, right? >> they're basically looking -- >> it's a yes or no, sir, so i'm going to object. >> yes, partly. >> they're looking at things beyond a nanosecond. agreed? >> i mean, i think in terms of a

pathologist, they're looking at half a nanosecond. they're looking at the nanosecond of death. >> but they're taking things into consideration in that instant beyond physiology, correct? >> they're looking at the cause. >> what causes the heart to stop, what causes the lungs to function, correct? >> they're making a space at a pathological time point. >> consider a multitude of biological factors that are involved in the death of a person, right? >> it's the same as any physician. they are looking at a multitude of factors. >> so in terms, again, of your review, you would agree that the

amount of time you've spent looking at videos, analyzing these videos from different perspectives and angles is far greater than the length of this incident. >> yes. >> probably to the time of a thousand. >> i really don't know. it's substantial. >> and ultimately you conclude mr. floyd died a what we call a hypoxic death. >> he died of a low level of oxygen. >> that there was a low level of oxygen that caused damage to the brain which resulted in a pulseless activity, correct? >> he had a low level of oxygen that caused damage to the brain. the brain didn't cause the pulseless activity. the low level of oxygen caused both. the low level of oxygen caused the damage to the brain. the low level of oxygen

separately caused the hypoxic death. >> so it's a result of multiple things occurring simultaneously? >> it's the low level of oxygen that's doing both. >> it's having an effect -- the heart and the brain and the lungs, right? >> not really, it's just two, the brain and the heart. >> brain and the heart. all right. you talked about -- i think you talked about -- is it the nucleoligament? am i saying that correctly? >> yes. >> that's that space at the back of the neck that's really hard, right? >> it's roughly at the palm of your hand when you stick your hand at the back of your neck. >> and that's, you said, a very, very hard surface, right? >> yes. >> you withstand a great amount of pressure, right? >> correct. >> so when we talk about the placement of the knee, there would be periods of time where mr. chauvin's knee was placed at

that nucoligament, based on your observation? >> yes. >> you've had an opportunity to review the autopsy, correct? >> yes. >> you understand there was no bruising either atop the skin or under the skin surfaces that were noted by dr. baker? >> yes, i'm aware. >> and you also are aware, you talked quite a bit about the hypopharynx. you are aware there was no injury to that? >> i'm aware. >> there was testimony in your report where you were talking about this notion of if you can speak, it doesn't mean -- sorry -- if you can speak, you can breathe, right? >> yes. >> and you described this as a

very dangerous proposition, right? >> yes. >> you described this as causing a false sense of security to people, right? >> correct. >> and, in fact, in your report you actually write a paragraph about how physicians oftentimes have trouble with this, right? >> yes. >> and so people who, similar to yourself, attended medical school, right? >> right. >> sorry, you have to say yes. >> i'm sorry. yes. >> intelligent men and women who have graduated from college, gone on to medical school and are engaged in the practice of medicine sometimes have problems with this notion, right? >> yes. >> a patient comes in and says they're having trouble breathing, and oftentimes a physician will not believe them, essentially?

>> it's important to note to make sure we're talking about speech or difficulty in breathing, because they're different. >> right. you write in your report that some doctors incorrectly consider patients to be hysterical. >> your honor, may we approach? your honor, the report is hearsay and it's not proper. >> overruled. >> you wrote in your report that some doctors consider cases hysterical which further aggravates patient distress, right? >> yes, as i recall. >> and this undermines a physician's failure to make a diagnosis? >> this is about hypotoxic failure. we're talking apples and oranges. >> but if someone comes in and

they articulate to their physician, i can't breathe, and it's hyperventilating syndrome, right? >> correct. >> and doctors sometimes confuse this issue, right? they blame the patient. >> i don't know if they blame the patient, but they certainly miss the diagnosis. >> and it's kind of -- when we're talking about speaking and breathing simultaneously, which is a different consideration, if a minneapolis police lieutenant who trains police officers happen to have testified that that's a common statement in the course of treatment or in the course of training of minneapolis police officers, you might take exception with that statement. >> i didn't follow your question. it's very hard to hear with the plexiglass. >> and i'm losing my voice.

if i minneapolis police officer -- i'll try to talk closer to the mic -- if a minneapolis lieutenant that trains police officers says to police officers that if a person can talk, it means they can breathe, you would have a problem with that? >> yes. they're able to breathe at that moment in time, but ten seconds later, they may be dead. >> and because dealing with any person is a rapidly evolving situation that can change from second to second? >> yes. >> now, in terms of the calculations that you've made, you would agree that your calculations are generally theoretical, correct? >> no, they're not theoretical.

they're based on direct measurements. they're based on extensive research. >> but you're making certain assumptions in the application of that science, are you not? >> very few assumptions. >> you're assuming the weight of mr. chauvin. >> right, i am aware. obviously i'mchauvin. >> right, i'm aware. obviously aware there are two different weights given. >> and you're assuming the weight of the equipment that the officers wear. >> yes. >> and you've actually not physically measured the weight of the equipment a police officer carries, correct? >> no. i mean, i took the measurements that are important. >> and you're not actually weighing what mr. chauvin weighed on may 25th of 2020. >> no. and in your measurements you appear to be, at least from my understanding, which is going to be limited, from my understanding is that your measurements assumed an equal

weight distribution between the right and the left legs. >> yes, that's correct. >> so again, as we know, as things change and evolve and flow, that's -- weight is pretty frequently redistributed, right? >> that is correct. and again, in terms of the eelv, am i saying that right? >> yes. >> that's the -- >> you're basing those calculations on the presumption the person is a healthy individual. >> in eelv, that could change. >> in terms of some of the other factors that you put into your

analysis, -- >> and those volumes or those figures that you've assessed in connection with this case, they are conditioned upon him being a healthy individual. >> i mean, it varies in terms of the lungs. say, for example, compliance would very but end rate lung

volume is -- >> what was the first one? >> lung compliance would vary from one person to the next person. it varies, different segments within the lung. they're not all monolithic. >> now, you talked about one thing in terms of -- this is a little bit of an aside. in terms of the prone position and the pushing of the stomach into the lungs, right? >> yes. >> the size of a person's stomach as some bearing on that, right? >> it does. >> a person like myself who has a few extra inches, if i'm prone, it's going to perhaps push further or harder up into my lung, right? >> yes. >> a person who is healthy, physical, muscular, it's going to have less of an impact. >> that is correct. >> but again, in terms of what we have learned about mr. floyd from his autopsy and his medical records, is that we understand that mr. floyd had some heart disease, right? >> that is correct. >> in fact, i believe that he

had in some of his arteries somewhere between a 75% and 90% occlusion of his ventricular arteries, right? >> correct. >> that's going to affect blood flow in a person, right? it going to make the body work a little harder to get the blood through the body. >> no, not really. it's not going to do that. >> how does that affect a person's respiratory -- >> the coronary artery? >> mm-hmm. >> the coronary artery is affecting it. and if the coronary artery was contributing to shortness of breath, you would expect he would be complaining of chest pain and you would expect that he would be demonstrating a very rapid respiratory rate. we don't see either. >> okay. we'll come back to the respiration -- i can't say it right. i'm taken by your accent. the respiratory rate.

>> i try and compensate for it. >> appreciate it. i'll say it like you, his respiratory rate. >> there you go. >> we also understand that mr. floyd based on his medical records has a history of hypertension or high blood pressure. >> yes, that's correct. >> now, in terms of we also understand that mr. floyd had previously been diagnosed with covid-19, right? >> correct. >> and he may not have been symptomatic on march 25th, but it's fair to say that a lot is unknown about the effects of covid-19 on a person's lungs long term. >> i mean not as much as it would appear to be the case. we have a huge amount of information about the long-term

effects of viral illnesses. >> it can effect the elasticity of the lung, right? >> not elasticity. it would be the receptor within the tracheal bronchial tree. >> you said treatment includes leaving them in the prone position. so those people treated for covid-19 in the prone position, based on your calculations, you would have a 24% decrease in the eelv. >> in is people with covid during the time that they have covid. >> right. >> but that's what you'd expect, that same decrease in the eelv. >> no, it's going to be very different in somebody who has, say, pneumonia, what's going to happen in the prone position

will be very variable from one person to another as a result of the pneumonia. it's different than normal lungs. >> okay. so in essence, every person is different. >> oh, for certain. >> and now you calculated his respiratory rate to be 22, right? >> correct. >> and you said that that was within the normal respiratory rate? >> yup. >> and you would not describe him as hype r >> and you would not describe him as hypeventilhyperventilati. >> the word hyper ventilation is open to a lot of interpretation. that is certainly not hyper ventilation. >> and hyper ventilation assists in the removal of carbon dioxide from the body. >> it's confusing. it's not that simple. >> in the simplest terms. >> the simplest terms it gets rid of carbon dioxide.

it can be frequently misleading. >> in terms of the toxicology of mr. floyd, we did learn that there were some controlled substantials in his system, right? >> yes. >> we know there was nicnicotin right? >> yes. mr. floyd was a smoker. >> yes. >> and smoking changes the lung function, agreed? >> in some people. >> we also learned -- and i'm not suggesting that people -- all people who smoke have lung problems, right. >> less than 10% do. 90% don't have any. >> can i ask you to back up a little bit from the microphone. >> i'm sorry. >> no problem. >> so you focused in your direct examination quite a bit in terms of fentanyl and the fentanyl's effect on the respiration rate. >> yes.

>> and you would agree generally that fentanyl is a respiratory depressant. >> it can be. >> it's used in operating rooms, right? >> yes. >> and it's also used in the management chronic pain, right? >> that is correct. >> and medically speaking, those are really the only two reasons that fentanyl would be prescribed. >> yes, probably. >> but you understand that fentanyl has become far more prolific in street drugs, right? >> yes, i'm aware. >> and you would agree generally that there is a significant difference between fentanyl that's manufactured according to the united states, you know, their whatever rules apply, right? the pharmaceutical companies make it much differently than the street dealers do, right? >> i imagine so. >> and so when you are -- when a

person is ingesting illicit street-purchased fentanyl, every time they take a fentanyl dose, it's a different effect for that person. >> if it's affecting the respiratory system, the reseptemberors, there's no way around that. fentanyl isn't going to have an effect by some other mechanism. >> understood. but the end result of fentanyl can include respiratory depression? >> right. >> we also learned there was methamphetamine in a low dose in mr. floyd's system, right? >> correct. >> and the fentanyl and methamphetamine can kind of counteract each other, right? >> they're uppers and downers. in terms of the respiratory center there's not going to be. >> so the methamphetamine is going to increase the heart rate, right?