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?

>> that's a different thing thank the respiratory center. >> methamphetamine will increase a person's heart rate, right? >> yes. >> that's one of the side effects. >> yes. >> lawfully there are a few conditions where a physician can lawfully describe methamphetamine, right? >> yes. >> but it's exceedingly rare that it's actually done. >> i can't say. but it's definitely a prescribable agent, commonly used for appetite suppress ent. -- suppressant. >> and i think adhd? is that right? >> yes. >> so we also know that adrenaline will increases heart rate, right? >> yes. >> and adrenaline can be put into the body in multiple ways,

right? >> i'm not sure. >> well, let me -- there are many things that can cause a surge in adrenaline. >> yes. >> one of those things would be getting into a fight with someone? >> yes. >> or being afraid. >> difficult to know in terms of being afraid but getting into a fight. >> and paragangli oo noma, i understand you call it the 10% tumor but in 10% of the case, that can cause an adrenaline surge. >> now, in terms of the use of fentanyl in the hospital setting, surgical setting, have you become familiar with what's called wooden chest syndrome? >> yes, i have. in some patients with fentanyl you get an increase in chest wall stiffness. >> so the lungs become less

elastic? >> not quite the lungs. the chest wall. >> so that would prevent a chest wall rigidity will also decrease the performance of the lungs? >> it will impede the ability. lungs to impact, to extend. >> now, in your report you wrote that you would expect the peak respiratory depression to occur from fentanyl within five minutes of ingestion. >> right. >> and have you come to learn that tablets or controlled substantials were found in the become seat of squad 320? >> i mean, i've heard reports to that effect. i don't know what the status of it is. >> so you were not -- you've not been provided with any additional information since the

time you've prepared your report? >> no, i'm sure that's wrong but i've been provided with a lot of information. i don't necessarily recall -- keep it all at the front of my brain. >> okay. well, yesterday we heard testimony from the state crime lab that there were in the back seat of the squad car two partially consumed pills found in the back of squad 320. >> objection, your honor, to the characterization of testimony. >> to the characterization of -- >> i'll overrule that if it's foundational. >> it is. you understand that? >> no. i kind of but not fully. >> okay. yesterday a chemist from the state crime lab testified in this case.

>> my ruling is sustained. you can state in the form of a hypothetical. >> i'm sorry, i can't hear you. >> side bar. i want to bring in our guests for the first half hour here. we've got kirk buckhalter, a new york school law professor and shanna lloyd, managing attorney for the cochran firm in orlando. if we have time -- it appears we

don't. let's go back to the trial. if partially ingested pills that were determined to contain both fentanyl and methamphetamine were found partially ingested in the back seat of the squad car and that those pills had been -- had come -- had the dna of the deceased individual on them, meaning that they took them and those pills would have been in his mouth at about 20:18, right, is it fair to say that you would expect the peak fentanyl respiratory depression within about five minutes. >> right. i mean, obviously it would depend on how much of it was ingested. just finding the pills won't tell you anything about whether any of it was ingested or some

of it or anything. but if there was any amount of it ingested, yes, the peak would be five minutes. >> and so if it happened at 20:18 or thereabouts, you would expect the peak respiratory depression to be around 20:13 -- 20:23, i'm sorry. >> you're trying to really confuse me, mr. nelson. >> i'm sorry. i think i can actually say it's been a long week now. so 20:18 is the ingestion point. you would expect peak respiratory depression by 20:23, right? >> right. >> the peak meaning it could continue afterwards, right? >> right. >> all right. >> you also described in your direct testimony what you have interpreted to be an anoxic

seizure at 20:24. >> 20:24:21. >> and that was what you saw and the jury was played, it was reflected from officer lane's body camera, right? >> correct. >> and it was the kick of the legs, right? >> yes. >> and after that point you can see officer lane hold the leg down, right? >> yes. >> and you can see it kick up again, right? >> yes. >> let's try not to talk over each other. >> sorry. i have a tendency to go fast. >> that's what you recognized based on your 46 years of being a pulmonologist in your experience, right? >> obviously there was additional information from the hand, but i mean, the leg was

the key. >> and it would be reasonable for a police officer to interpret that same behavior as resistance. >> objection, your honor. foundation of the witness talk about what's reasonable for a police officer. >> sustained. >> now, you testified that the last breath of mr. floyd was at 20:25:16, right? >> correct. >> prior to that point to all people who were there and monitoring him, he would have appeared to have been breathing, right? >> it's just hard for me to hear. >> sorry. >> prior to that point, it would be reasonable that he would appear to be breathing, right? >> yes. >> and, in fact, you showed us a segment where you were able to count his respiratory rates. >> yes. >> right? and then you said that at

20:35:06 seconds is when the first air was pumped back in to him. >> correct. >> all right. and you understand that paramedics arrived at 20:27:45? >> yes. >> and so the time between when the paramedics arrived and mr. floyd got his first air was roughly eight minutes, almost nine minutes, right? >> yes. >> and according to timelines, the drive to the hospital was about five minutes? >> i'm sorry, i didn't catch that. >> were you aware that the drive to the hospital is about five minutes? >> i wasn't aware but i have no reason to dispute it. >> and so between 20:27:45 when the emts first arrived and the time they got him to having air

in his lungs, that was a crucial nine minutes. >> yes. >> your honor, i have nothing further. >> dr. tobin, just a few questions just for clarification sake. you were just asked a lot of questions about science and medicine changing, constant changing, evolving by the nano second, milli second, you heard all that in. >> yes, i did. >> i want to go to the period of time when the knee of mr. chauvin was on the neck of

mr. floyd? >> yes. >> did you see him got off the neck of mr. floyd in the millisecond, nano second. >> no, i did not. >> where was mr. chauvin the vast majority of that time? >> he was on mr. floyd's neck and on his back and arm. >> not constantly changing? >> no. >> you were asked questions about what injuries were noted on autopsy. >> yes. >> and i think reference was made there was no injury noted to the hypopharynx on autopsy? correct. >> does that make any difference to you whatsoever? >> no. i wouldn't spaekt it. >> why not. >> the type of changes we see

say in somebody with sleep apnea, that's not something you're going to see the following morning when you look at something. it just not there. >> there was also a reference made to the absence of bruising on the neck during autopsy. >> yes. >> does that make any difference to you whatsoever? >> no, because whenever i go to church, i sit on a hard bench. i don't get bruising of my buttocks when i leave. so i wouldn't expect anything in terms of that. so if you have somebody -- this was a static force. it's not as if somebody is jamming against it so you wouldn't expect anything in the way of bruising. >> reporter: scientifically, do you know of any correlation between the presence and absence of bruising on autopsy and the forces necessary to restrict breathing? >> no. they're totally different because it's in terms of static forces and dynamic. >> what about low oxygen? if somebody suffers or dies from low oxygen? >> yes. >> does that show up on autopsy?

>> no, it does not. >> and the fact that it doesn't, does that mean anything to you whatsoever? >> it has no meaning. >> and why not? >> because low oxygen is a functioning thing just like an arrhythmia is a functional thing. it doesn't leave a fingerprint on the autopsy. it's just there. it's something that happened but it won't leave any fingerprint afterwards. you don't see it. >> but it doesn't mean that the person didn't die from low oxygen. >> no, absolutely not. so if you take somebody and you suffocate them with a pillow and it's very clear to you after you suffocated the person and he's dead from the pillow, you're not going to see the effects of the low oxygen. >> now, you were asked quite a few questions about mr. floyd's preexisting health conditions. >> correct. >> and you cited a number of those. >> yes. >> do any of those conditions have anything to do with the cause of mr. floyd's death in

your professional opinion whatsoever? >> none whatsoever. >> and, again, what was the cause such that those conditions don't matter? >> the cause of death is a low level of oxygen that caused the brain damage and caused the heart to stop. >> you were also asked questions about substances in mr. floyd's system. i think you were asked questions about nicnicotine. remember that? >> yes. >> he didn't die from nick oaf teen, did he? >> no. any evidence that he died from meth? >> no, none. >> you were asked questions about whether he had ingested any fentanyl within five minutes of his time of death. >> yes. >> now, i think you explained to us that if somebody is suffering from from a fentanyl overdose, you would see a depression in the respiratory system. >> yes. >> and depression means some reduction in the rate or ability to breathe. >> correct.

>> did you see any depression in mr. floyd's ability to believe before he went unconscious is this. >> no, absolutely not. it was normal respiratory rate. >> any evidence that any fentanyl in his system depressed his breathing whatsoever? >> no. and that's further born out in the carbon dioxide? >> anything further? >> briefly, your honor. two very quick questions. in terms of the carbon dioxide level, you testified that it was at a 96? >> yes. i'm sorry, i didn't catch it. >> you testified that the carbon dioxide was at a 96? >> i think it was 89. >> 8 9. it was also measured at 102. >> that's the venus one. the arterial is the one you need to look at. >> in terms of the ingestion or just generally speaking fentanyl

can also cause low oxygen to th right? >> it would have to relate to respiratory depression. >> fentanyl can also cause a death as a result of low oxygen. >> your answer is yes but only in part. >> fair enough. thanks. >> briefly. >> just one, your honor. mr. nelson brought up against fentanyl as a cause of death, doctor. >> yes. >> you're familiar with the way people die from fentanyl. >> yes, very. >> do they or do they not go into a coma before they die from a fentanyl overdose? >> yes, they will. >> was mr. floyd ever in a coma? >> no. >> thank you, dr. tobin. >> okay. >> anything else? >> no. >> thank you. >> doctor, thank you so much. you are excused. >> okay, thank you.

>> the defense there trying to introduce some reasonable doubt by introducing the role that fentanyl might have played in george floyd's death. but among the takeaways there were dr. tobin stating declare tifl that the cause of death was a low level of objection johnson. joining us is a love -- law professor. shanna, dr. tobin, this veteran lung doctor, earlier today testified that george floyd's death was caused largely by derek chauvin's knees pressing against his neck and back making it impossible for him to breathe and that mr. floyd showed signs of a brain injury about four minutes before derek chauvin actually lifted his knee from his neck. has the defense been able to

undermine that testimony on cross? there was that point where tobin sort of laughed and said you're trying to confuse me, said it in jest. they're trying to make everything with certitude appeared to the jury that it's perhaps unknowable. >> i thought they were trying to cut into the testimony in key places where they thought they could get wins. this particular expert was very engaging and very clear and he actually took command of his own testimony, which you don't see often with these types of witnesses. nelson's ability to cut into this testimony wasn't as vong as i would have expected. this particular expert kept control of his testimony and kept it very succinct without allowing nelson to complicate it. >> there was a point at the beginning of eric nelson's

cross-examination that he made clear that dr. tobin wasn't accepting a fee for his testimony, he's not being paid. was the point to suggest bias that somehow dr. tobin's opinion of the case was so strong that he wanted to get involved and have a role in this because he is in some way biased? >> i would think so because the defense -- the prosecution presented that aspect as he is not biased, he is not being paid here, so, therefore, he's objective. so the defense certainly in their attempt to rebut that particular aspect is showing that, well, he's motivated by a higher purpose. and that's why he's here. it was very interesting the defense started off with literally attacking his credibility so to speak in that he did not do a direct examination of the decedent and also attacking his accent and making a comment about him being irish. and i don't think they won any points with that to be quite

honest with you. >> megan, what's the read on the jurors in the room earlier this week during parts of which the testimony had been more mundane, more technical, there was reporting that jurors were sort of perhaps distradistracted, no paying attention. how were they today? how have they been responding to the testimony? >> a clear contrast from what we saw a couple of days ago and what we saw today. the pool reporters are saying they're very engaged. it speaking about how people breathe and the science of it all is a bit dry but jurors are captivated. as shanna, mentioned, they were very engaged. what stands out is when the prosecution slowed down that video where you could see george floyd's face. and when dr. tobin mentioned,

you know, take a look there, you can see when his eyes start to close for the final time, dr. tobin then said that's the moment the life goes out of his body. and this a moment where jurors were taking notes, leaning in to the video and certainly worth noting that george floyd's family is inside the courtroom and they just continued to stare straight ahead. so obviously incredibly emotional moment for them as well but certainly a powerful moment there for the prosecution. >> shanna, what do you make of the sequencing of these witnesses, the prosecution bringing in dr. tobin after we've heard from police officials who basically have said that chauvin's use of force was excessive, yet we're hearing from dr. tobin before we hear from the medical examiner, who we might hear from as early as tomorrow. give us a sense of how this is all playing out. >> they're layering their case in an interesting fashion.

they started with this heavy emotional testimony. everyone is watching over and over. each juror is looking to see if they can so life, how it happened, what was happening. they they took them into the use force experts and training and all the questions jurors were asking themselves internally were answered by the facts. now we move to the science and this particular witness is pointing out a moment where he says this is his last breath. and so now all of those questions that jurors would have had based on watching this emotional video are being tied to these little factual witnesses. so it cementing whatever they might have felt or seen within the videos themselves. it's working well. it's tying the emotion to the facts and video that will support their case in chief. >> kirk, what do you make of the defense's attempts to introduce reasonable doubt, this question of fentanyl.

you heard the doctor say fentanyl played no role in mr. floyd's death. the defense came back and said there's a difference between pharmaceutical grade fentanyl and the stuff you get on the streets. what was your take? >> in layman's term, it was an excellent try had not the prosecution came back and performed such a masterful redirect. so what the jurors are left with, people usually recall the first and last thing they heard and what they're left with is the doctor testifying, well, yes, somebody could die from this or that. that wasn't the case here. why not? because they usually go into a coma. how did he die? and the doctor was age to opine on this causation issue and that's so important. so points to the defense for giving it a try, however, the prosecution i thought was rather masterful on how they came back

on their redirect. >> my thanks to the three of you. we're keeping our eye on the derek chauvin murder trial. we'll take you back to that courtroom as soon as testimony resumes. also coming up, president biden takes major executive actions on gun control. the first steps his administration is it taking to curb gun violence in america, what he calls a public health epidemic. you're watching "msnbc reports." " kraft. for the win win. 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, and fidelity will help her explore some different scenarios, like saving more every month. ♪♪ and that has carla feeling so confident that she can enjoy her dream...

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good afternoon, sir. >> good afternoon. >> where do you work? had. >> i work at mns labs in horschel, pennsylvania. >> what do you do? >> i'm a forensic analyst. >> from 1994 to 2011 i was the chief toxicologist for the way county medical office and i was the director of toxicology. prior to that from 1982 to 19

1991, i was at maryland medical labs from '84 to '86 at the medical examiner's office in baltimore as well. >> so rewinding a bit to your educational background, could you describe for the jury what your educational background is. >> i have a bachelor's degree in biology from adelefi university obtained in 1982. i have a masters degree in forensic pathology with a concentration in forensic toxicology from the university of baltimore in 1986. and then my ph.d was from the university of baltimore in forensic toxicology in 1991. >> do you have any specialized certifications? >> specialized it board of fellows of the toxicology.

>> you can apply to the board after three years after you have your ph.d. they examine your credentials to see you're active in the field of forensic toxicology. if you have the right references and you're active in the field, they will allow you to sit for an examination. if you pass the examination, the board votes on your final certification. after that, you have to do continuing education each year and attain a minimum number of continuing education credits and every five years you have to reapply to the board for reaccreditation. >> have you gone through all those requirements? yes, i have. >> are you up to date with all the continuing education requirements as well? >> i am. >> i'm going to get back to your control as a forensic toxicologist. can you describe your day-to-day job duties. >> my primary responsibility is

to do case review and what that means is when toxicology tests are performed at nms labs, particularly ones that require many different kinds of tests to be done, they wind up being reviewed by a toxicologist or certifying scientist to look at them in the context of all the testing that was done. so individual tests are reviewed by analysts in the laboratory and they're secondary reviewed as well but the final review comes to either a toxicologist or certifying scientist that looks at everything in the context of the entire case. >> and is it part of your job duties to sign off on all that testing? >> yes, it is. i review about 7,000 to 8,000 cases per year. >> and in terms of the work that comes in to nms labs, are there a variety of agencies that

submit samples for testing? >> yes, we get samples from medical examiners and coroners and from police agencies, for dui cases and a lot of clinical samples from hospitals and referral laboratories. >> so in that capacity, does nms receive both postmortem or death-related samplesas well as samples from living patients? >> yes, we do. >> as a lab, approximately how many samples do you receive each day? >> about 1,200 to 1,300 requisitions each day. >> what you say requisitions -- >> it would be requests for tests. >> so thousands of tests a year. >> thousands of tests a day. >> tens of thousands of test as year. my math is bad.

is nms a licensed and accredited lab? >> it is. >> does that include national accreditations as well? >> national and state accreditations. >> i'm going to turn to your work in this particular case. did nms labs receive some samples for testing from the henpin county medical office related to george floyd? >> we did. >> were there a number of different samples that were received? >> correct. >> what were the samples that were ultimately tested by nms labs? >> we tested the samples that were requested by the medical examiner to be tested. we tested samples labeled as hospital blood and also tested urine that was collected at the autopsy. >> and in terms of the testing that was performed at nms labs, were those tests pursuant to standard operating procedures at the lab? >> yes, they were. >> and that process was followed for all of those tests?

>> yes. >> getting to the results from that testing, what were the notable findings from that testing? >> so the most notable findings in the hospital blood was the presence of fentanyl and 11 nan o grams and nor fentanyl had 5.6 nanograms per milliliter. >> i'm going to talk about each of those substances one by one. you indicated these were the results from the hospital blood in this case is that right? >> that's correct. >> what is methamphetamine? >> methamphetamine is a central nervous system stimulant. it can actually be prescribed, it rarely is but it can be prescribed under the brand any

dijoxin, used for hyper activity, for obesity. >> can it be a street level recreational drug and prescription drug? >> it can. >> with the results of methamphetamine, what significance is there to that amount? >> that is the approximating amount you would find in the blood of somebody that was given a single dose of methamphetamine as a prescribed drug. >> so when you say you described the prescription drug form in width methamphetamine can be available, the results would be a prescription dose?

>> yes. >> would that be a low level? >> yes, a low level. >> what is fentanyl? >> fentanyl is an opioid analgesic. it's used similar to morphine. it's much more potent than morphine. it can be used to treat pain and also be an adjunct use in surgery for anesthesia. >> and you talked about open -- opioids. maybe you can describe what an opioid is. >> they include both natural, semi-synthetic and synthetic drugs that act on a receptor where opioids act. opiates are a natural product found in morphine and codeine.

opiates are opioids but not opioids are open. >> would oxy codon be an opioid? >> yes, it would. >> you talked about similarities between opioids and opiates, is that right? >> yes. >> you mentioned morphine as an opiate? >> yes. >> is that heroin? >> so heroin is actually made from morphine but when heroin breaks down, it breaks down into a met tab light call syxocital morphine. >> do they have similar effects? >> yes. >> getting back to the fentanyl level in this case, can fentanyl levels vary widely defending on an individual? >> yes, they can. >> and why would that be?

>> because of tolerance. >> could you just explain how an individual's drug tolerance might affect the impact on them? >> if a person becomes tolerant to a drug, you need to have more and more of the drug to get the desired effect. so with chronic use to get the same feeling that you would at a given concentration of fentanyl, you need to take more to get that effect. >> if someone is regularly using opiates or opioids, would that person develop a toerance? >> yes. >> can you describe what nor fentanyl is? >> it breaks it down. it's a gradual process and it one of the ways that the body

eliminates fentanyl. >> the amount of norfentanyl found was 5.6 milligrams? >> yes. >> what is significant about that amount of norfentanyl? >> it shows some of the fentanyl was metabolized to norfentanyl? there could be preexisting fentanyl. but basically shows that when we see very recent deaths with fentanyl, we frequently see fentanyl with no norfentanyl whatsoever. after an acute intointoxicatione body doesn't have time to break it down. >> in addition to those findings from the hospital blood, were there other findings as well that were included in your report? >> there were. there were some incidental

findings. i believe there was codeine with some smoking, there was caffeine, there was evidence of prior marijuana use, the presence of kanaveniods. >> if we could put on the screen exhibit 624 and zoom in on the positive findings portion. all right. referring to your report now, could you describe the other findings with respect to this case. >> yeah. so the additional finding was a compound called 4 anpp, that is actually a precursor to fentanyl manufacturing but it is also a met tab light of fentanyl. it not farm kol logically significant and is probably mostly inactive but it was

measured as additional testing. urine finding were not confirmed for amphetamines. fentanyl was found in the blood and opiates in the urine and we found a concentration of morphine in the urine of 86 nanograms per milliliter. >> you said 86 nanograms per milliliter? >> yes. >> was that found in the blood? >> no. >> can a finding of morphine in urine being indicative of a prior use in advance of the time of death? >> yes, it can. you can see morphine in urine for several days depending on the dose and prior use pattern.

>> again, is that because it shows up in urine longer than blood? >> yes. >> you were also discussing the 4anp finding with the hospital blood. with respect to the other findings in your report, can you summarize what they were and whether they were significant at all. >> i think i mentioned so there was caffeine, which was present in many of us and coatanine, which is present as a metabolite and 11 hydroxy and inactive

delta. >> and what if any impact does that have? >> it's very hard to interpret that given the nature of the samples and also what happens with canavenoids because they go into the fat and can be released in time and anything with cpr will release thc. >> so they can remain in the system and be detected for an extended period of time. is that right? >> yes. >> okay. we can take that down. thank you. >> now, as part of your testing process at nms labs, were there also some metabolyted detected but below reporting limits?

>> we did find substances below the require to report but they were part of the data package that was requested. one can see those there. >> and do you keep those litigation packages or that data as part of your standard operating procedures over the course of business at nms labs? >> all of the data is part of the course of business. the litigation package is actually pulled from that data on request but yes. >> so as part of your testing, the lab's testing of samples in this case, i'd like to ask whether there was findings for amphetamine. >> the screen was positive by methamphetamine. anything positive above a certain threshold by that procedure is then confirmed by an alternate procedure. methamphetamine was positive on

the screen and we ran the con confirmation tests. we're only interested in target compounds we are actually confirming in this case. in this case we did detect methamphetamine and because it there was evidence of amphetamine but it was below the reporting limit so it was not reported. >> and amphetamine is a met tab light of methamphetamine, correct? >> and do that mean that it breaks down in the body from methamphetamine to amphetamine over time? >> yes in. >> and was there an indication of bumorphine? >> it was not confirmed and was

merely an indication. >> that means it didn't go through the second step of the process? >> what is bupor morphine? >> it's called suboxone and is prescribed for people going through opiate treatment. >> and are the components of suboxone -- is it generic narcan? >> yes. >> you indicated that the blood was hospital blood, is that right? >> yes. >> what's significant about using hospital blood for testing? >> well, hospital blood, if it's anti-mortem blood, it more representative of what is circulating in the body prior to the time of death. after death there are changes that occur with drug concentrations, particularly in

central blood collected from the heart. that is known as postmortem redistribution where drugs go from areas of higher to lesser concentration. that's less of an issue with peripheral blood samples such as femoral blood but it can still occur. ideally you want a simple as close to the time of death at possible. >> if a sample is taken after death or after extension cpr on a patient, can there be postmortem distribution sm. >> it is possible and if it does, it tends to increase concentrations. >> does that mean the level might show higher than it was at the time of death? >> yes. >> what's homolysis?

>> break down of the red blood cell. >> did that have an impact on the testing in this case in. >> no. when you analyze a blood sample for drugs, you're analyzing the whole sample so it would have no effect. >> so you mentioned that nms labs receives thousands of samples a day, tens of thousands of samples a year. did you review and compile some data from the year 2020 with respect to nms's fentanyl cases and methamphetamine cases? >> i did. >> would those help to you contexturalize the results in this case? >> yes.

>> i would offer the exhibits. >> any objection for demonstrative purposes? >> what was the number again? >> i'm sorry, your honor? >> exhibit number? >> 920. >> 920 won't go back with you deliberation but will be received for illustrative purposes of testimony. >> and if we could publish. thank you, your honor. doctor, i'm going to have you describe what's shown on this

screen. >> so as of right now we're looking at what happens when fentanyl is metabolized metabol. >> and that's what happens as the body metabolizes fentanyl? >> that's correct. >> all right. next slide please. if you could describe what's shown here? >> data from nms labs from year 2000 and we looked at the fentanyl concentrations in postmortem cases in those and only those collected in peripheral blood for the reasons i mentioned before. central blood like cardiac blood can have a significant postmortem redistribution and wanted to look at -- >> i think you indicated 2000. is this from 2020? >> my mistake. this is from year 2020 why we

have 19, 185 cases we looked at and in the peripheral blood and the postmortem cases the mean fentanyl concentration, average is 16.8 nanograms per milliliter and the median concentration is 10 median being 50% above and 50% below. >> and with respect to peripheral blood you chose the samples that would have minimum redistribution. is that correct? >> correct. >> why is that in comparison to this case? >> because the sample that we had of hospital blood is probably going to have less issues with postmortem redistribution than had it been postmortem blood. >> the cases that are represented as postmortem cases, are these cases you get from m.e. offices or coroner's offices? >> correct. >> where the individual is deceased or dead?

>> correct. we also looked at the norfentanyl concentrations and those were 6.01 as a mean and the median at 2.2 nanograms per milliliter. >> to clarify with respect to the postmortem cases the average level of fentanyl is 16.8 and the average level of norfentanyl is 6.01 nanograms? >> correct. >> what's shown here. >> so this slide shows some postmortem cases with no norfentanyl for the year 2020. so out of those 19,185 cases, 15,455 that included fentanyl and norfentanyl but 3,724 cases with no norfint nil. six were exceptions to that for reasons of testing purposes but those are the ones that were

only fentanyl. >> does this slide indicate a significant number, 3,724 cases where there was fentanyl found but no norfentanyl at all? >> correct. >> all right. next slide please. what's shown here? >> so this is a switching gears. this is looking at the dui driving under the influence fentanyl concentrations we found in 2020 so these are blood samples sent to nms labs for people that were suspected of driving under the influence of drugs or potential other reasons, the way they were driving. and in this case we tested 2,345 cases. that were individuals that were alive that had fentanyl on board. of course, other drugs may also be present but this is specifically looking at fentanyl and a mean concentration of 9.59

ma no grams of millimeter. and innocent norfentanyl. >> again, just to clarify for the 2,345 cases the evenings were alive. is that right? >> correct. >> you indicated the average is 9.59? >> yes. >> and the average norfentanyl level is 5.42 nanograms per milliliter? >> yes. >> next slide please. what's shown here? >> this is a breakdown of the concentrations we found in drivers that were alive. so almost the majority of them under 5 nanograms of milliliter of fentanyl and then another 26.3%. and then the next set of data was 216 cases which were between

11 and 15 nanograms per mill and in the same level of mr. floyd's. and then we had several, quite a few cases that were greater than that. we had 109 between 16 and 20. 81 that were between 21 and 26. 133 between 26 and 50. and then 53 cases in living subjects with fentanyl greater than 50 grams of fentanyl per milliliter. >> comparing to the driving population where individuals were alive, his level was within a quarter of the pie of the dui cases that nms labs received. is that correct? he would be in there with 80th percentile. >> those levels for drivers were found in 53 cases higher than 15 nanograms per milliliter.

>> correct. >> those vujacics were alive -- >> we have been listening to testimony of this doctor, a forensic toxicologist. still with us is former nypd detective kirk burkehalter and joining us is attorney, the lead prosecutor in the bill cosby trial. kristen, among the take aways from this doctor he said that the amount of methamphetamine in george floyd's body consistent with the dose of prescription methane a low amount. and the prosecution was also asking him questions about how high tolerance for fentanyl impacts the overall effects and the reason i imagine that's important because we heard in earlier testimony from george floyd's former girlfriend that mr. floyd had a high tolerance for fentanyl. what is the prosecution trying to achieve with this particular loon of questioning? >> i think the prosecution is

trying to show several things and quite frankly i think they're doing it effectively and the defense is -- their argument is hit a wall today why what they're trying to show is that based on other nms testing the toxic things in mr. floyd's bloodstream specifically the methane the fentanyl are within normal levels and there have been other evenings specifically those driving under the influence still alive with the same levels that were found in mr. floyd. the crucial element that the prosecution has to prove is the substantial causal factor in the death is oxygen deprivation and i think from hearing from dr. to been and nms person that tested mr. floyd's blood saying normal levels and he also went an extra step to say this was the

hospital blood that i tested and so the levels that i tested would have been higher than what was in mr. floyd's bloodstream at the time and i think it really undermines any argument that mr. floyd died of a drug overdose. >> kirk, to kristen's point, she brought up the testimony that veteran lung doctor and heard from him previously i think it was on redirect saying that nothing everything is seen in an autopsy. why is that a critical point for the prosecution to get on the record? >> that's extremely important because the prosecution has made this point over and over about the lack of visible bruises on the corpse, the lack of other indicators that might show that the chauvin had the knee on floyd's neck and the witness made the point of i sit down in the church pew and the bruising

doesn't remain with me. i agree. this is an excellent bookend to the previous witness because here the forensic toxicologist can state that different things happen to the chemicals once someone is deceased via an overdose and this testing doesn't show overdose whatsoever so it's a nice book end to the information that the previous witness set forth for the prosecution. >> and, kristen, what are the unintended consequences of the defense trying to prove an overdose theory? >> absolutely. i think it feeds into racial tropes and goes into old theories. he was struggling with drug addiction and many people in america are but to point that's the overdose, that is the cause of death and undermined by the medical testimony and battle of

the experts and keep in mind they only need one juror. >> kristen gibsons and kirk, i appreciate you both. msnbc will keep an eye on the events in the courtroom. meantime "deadline white house" with niccole wallace starts right now. hi there, everyone. it is 4:00 in the east. there's new developments in court today that could be a sign that the walls are closing in on one of the former president's most prominent and vocal political allies. florida republican matt gaetz. from "the new york times" in just the last few hours, quote, a former local official in florida who faces an array of federal charges including a sex trafficking count is expected to plead guilty in the coming weeks a prosecutor and defense lawyer said on thursday in an indication that the defendant could cooperate as a key witness against representative matt gaetz under investigation. a plea