Day 9 brought some very powerful scientific testimony in regards to George Floyd’s cause of death.
Dr. Martin Tobin, a world-renowned pulmonologist and critical care physician at Loyola University Medical Center and at the Hines Veteran Administration Hospital in Illinois, was called as an expert medical witness for the prosecution.
Dr. Tobin testified that George Floyd died from a “low level of oxygen” when former police officer Derek Chauvin pinned him to the street and restricted his ability to breathe.
“The cause of the low level of oxygen was shallow breathing,” he added. “Small breaths. Small tidal volumes. Shallow breaths that weren’t able to carry the air through his lungs down to the essential areas of the lungs that get oxygen into the blood and get rid of the carbon dioxide.”
He identified four main reasons why Floyd died:
- The handcuffs and the street acting as a “vise”
- Chauvin’s left knee on his neck
- Floyd’s prone position
- Chauvin’s right knee on Floyd’s back, arm and side
Combined, these limited Floyd’s ability to expand his lungs and narrowed his hypopharynx, a part of the throat that air passes through. Tobin stated that Floyd was essentially “squeezed to death” as if he were in a vise.
Floyd’s preexisting health conditions and drug use were not relevant to his death, Tobin said. “A healthy person subjected to what Mr. Floyd was subjected to would have died,” he said.
Dr. Tobin highlighted several still images from the police body-cam footage that showed Floyd pressing his knuckles against the squad car’s tire, pressing his fingers and knuckles against the ground, lifting his right shoulder and even digging his face into the street. “These images indicated that Floyd was using every possible way to try to lift up his chest and breathe,” Tobin said.
Prosecutors also played disturbing slow-motion video of what Tobin said was Floyd’s final moment alive, as his eyes flickered and then closed. “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,” Tobin said. He also highlighted a moment in the body-camera footage when Floyd’s legs lift into the air. This involuntary movement, also known as an anoxic seizure, is evidence of a fatal brain injury due to lack of oxygen
Dr. Bill Smock, an emergency medicine physician and the police surgeon for the Louisville Metro Police, also testified Thursday for the prosecution as a medical expert. He concurred with Dr. Tobin’s analysis of Floyd’s cause of death.”Mr. Floyd died from positional asphyxia, which is a fancy way of saying he died because he had no oxygen left in his body,” he said.
Smock rejected the idea that Floyd died of “excited delirium,” a controversial diagnosis that is not recognized by either the American Psychiatric Association or the American Medical Association. Smock said he believes it is a real diagnosis — but Floyd showed none of its 10 symptoms, such as taking off his clothes or failing to respond to questions. He also rejected the theory that Floyd died of a fentanyl overdose. People who overdose on fentanyl become listless and stop breathing, while Floyd was desperately trying to breathe. “That is not a fentanyl overdose. That is somebody begging to breathe,” he said.
Also testifying on Thursday was Daniel Isenschmid, a forensic toxicologist at NMS Labs who analyzed Floyd’s blood, testified Thursday afternoon about the levels of drugs found in Floyd’s blood after his death.
Testing found that Floyd had about 11 nanograms per milliliter of fentanyl in his blood. That is comparable to the level found in people arrested for DUI, but lower than the level found in people tested after death, Isenschmid said. “The impact of fentanyl on someone can vary from person to person due to tolerance,” he said. Floyd also had 19 nanograms per milliliter of methamphetamine in his system, a “very low” level, according to Isenschmid.
Day 10 started off with a juror being questioned about possible misconduct.
Judge Peter Cahill questioned one of the jurors, a white woman in her 40s or 50s, about her receiving a text from her mother-in-law. The juror told the court that she received a text saying it “looked like a bad day.” The judge responded by asking if the woman was working on a “book deal.” It was not clear whether or not he was joking. The juror responded by saying that she didn’t know what to expect from the trial.
The juror also reported that she briefly saw an outside attorney discussing the case on TV. She said she turned off the TV as soon as she noticed the courtroom. The judge concluded that the juror did not engage in inappropriate conduct and is still fit to serve.
Friday’s testimonies came from additional medical experts, including the medical examiner who conducted Floyd’s autopsy. Dr. Andrew Baker, the chief medical examiner for Hennepin County, stated that Floyd’s underlying conditions and drug use did not cause his death. He said that other factors that are believed to have played a role in the death but “didn’t directly cause the death,” get relegated to the “other significant conditions” section of a death certificate. Baker ruled George Floyd’s cause of death was “cardiopulmonary arrest complicating law enforcement subdual, restraint, and neck compression.” The manner of death was ruled a homicide. Dr. Baker also stated that he did not watch any of the videos of the event prior to performing the autopsy.
“Mr. Floyd’s use of fentanyl did not cause the subdual or neck restraint, his heart disease did not cause the subdual or the neck restraint,” Baker testified.
Dr. Lindsey Thomas, also a forensic pathologist, testified as well. While she did not participate in this investigation, she was one of Dr. Bakers trainers. When asked how she interpreted the medical examiner’s cause of death, Dr. Thomas said it meant, the activities of officers resulted in Mr. Floyd’s death. Thomas said she agreed with earlier testimony that it was law enforcement officers’ actions that led to his death — adding that there was not evidence from his autopsy or toxicology reports that he died of a heart attack or drugs.
“Specifically, those activities were the subdual, the restraint and the neck compression,” she said.
“What I observed from all of these videos is this was not a sudden death,” Thomas said, contrasting it to something like cardiac arrest induced by shoveling snow, in which “someone comes in and collapses, clutches their chest and falls over.”
“There was nothing sudden about his death,” she continued. “It was not the type of death that has been reported in fentanyl overdoses, for example, where somebody becomes very sleepy, and then gradually, calmly, stops breathing.”
On cross-examination, Nelson asked about Floyd’s heart, the dangers of the prone position, and drug use. The doctor agreed that Floyd had a “slightly enlarged heart,” with a restricted right coronary artery, and a history of high blood pressure. She also agreed that lying in the prone position alone is not dangerous, “not if there are no other factors.” In a hypothetical question, Nelson asked the doctor to consider if someone had the same levels of drugs in their system as Floyd had, with no other variables. In such a case, would she rule the death an overdose? “In the absence of any other realities, yes, I would consider that to be an overdose,” Thomas said.
On redirect, prosecutor Jerry Blackwell attacked that hypothetical. In his initial response, Blackwell described the question to be like asking Mrs. Lincoln if John Wilkes Booth wasn’t there if the president would have died. Nelson objected to the framing, and Judge Peter Cahill ruled it argumentative. Blackwell rephrased the question, asking the doctor if she’d ever assess someone’s manner and cause of death by removing facts that were central to the case. Thomas responded that she wouldn’t.
My take: Dr. Tobin was an excellent witness for the state. As a world-renowned pulmonary expert, his testimony was vital in detailing exactly how George Floyd died. This man has 40 years experience and basically wrote the book on the physiology of breathing. Not only is Dr. Tobin a wealth of knowledge, but he was able to explain everything so that the jurors could understand, and even went so far as to demonstrate to the jury and get them involved in feeling how Floyd died. He walked the jurors through a demonstration of their own neck anatomy, pointing them to the hypopharynx, which he called “vulnerable.”
With all of the experts we’re hearing from, a lot of it can start to sound like white noise. Knowledge is useless if it’s not explainable. Dr. Tobin excelled at scientifically explaining what happened, and doing so in layman’s terms at times. He also was strong through cross-examination, despite efforts by Nelson to trip him up.
The defense’s strongest argument in this case is that George Floyd died of an accidental drug overdose. We now have 2 medical experts saying, through detailed scientific testimony, that that is not the case. Tobin’s statement that a healthy person would have died under the exact same circumstances was also very damning to the defense.
The testimony from the medical examiners was also very compelling. I’m not certain how much Dr. Baker helped or hurt the state’s case. He was the only one not to say that George Floyd died from asphyxia. He also stated “Had Mr. Floyd been home alone in his locked residence, and no evidence of trauma, and the only autopsy finding was that fentanyl level then, yes, I would certify his death as due to fentanyl toxicity. Again, interpretation of drug interactions is very context-dependent.” He did confirm on cross-examination that he would still classify the death as a homicide.
Dr. Baker did an excellent job on cross-examination in regards to questions he couldn’t answer. Many things Nelson asked him to verify that were outside his scope, especially relating to asphyxiation, he always replied “I’d have to defer that to a pulmonologist.” Who we’ve already heard from, and verified the cause of death.
Eric Nelson is still struggling in his defense of Derek Chauvin. His interactions with witnesses have ranged from boredom, to annoyance, to outright frustration. I don’t think he is making any friends on the jury. His repetitive questioning is almost always pointed out by each witness. Basically saying, “how many times can I tell you the same thing?” Also, his hypothetical questions are so far out of the realm of possibility of even being remotely relevant to what happened to George Floyd. At one point in his cross of Dr. Baker, in trying to discredit his knowledge on how drugs affect the body, he asked about a hypothetical scenario involving a tropical disease. Again, just so far in the direction of wrong with this.
In addition, he comes across as smug and sometimes snarky. When Dr. Baker didn’t give him the answer he wanted about the cause of death, he then asked “The medical definition of homicide and the legal definition are different, agreed?” Keep in mind, Dr. Baker has already covered that homicide is defined as “death at the hands of another,” and that the death certificate specifically says “due to police restraint.” Nelson is reaching, and in doing so is coming across as combative.
In my opinion, Nelson is operating under the assumption that the jurors aren’t smart enough to understand this. Fortunately, the witnesses are doing a good job at alleviating confusion. His attempts at misdirection are not working in his favor. Next week we should begin to hear defense witnesses, so it will be interesting to see how he interacts with those witnesses.