MINNEAPOLIS – This was a video that everyone in the courtroom was shown repeatedly, of George Floyd face down in the street with Derek Chauvin’s knee on his neck. But this time it was slowed down so the jury could see the briefest widening of Mr. Floyd’s eyes – which the expert witness on the stand Thursday said was his last conscious moment.
“One second he’s alive, and one second he’s gone,” said witness Dr Martin Tobin, adding, “That’s when life comes out of his body.”
Dr Tobin, a pulmonologist specializing in the mechanics of breathing, presented the prosecution’s first extended testimony on an issue central to Mr Chauvin’s murder trial: how George Floyd died. “You see fatal brain injuries here from lack of oxygen,” said Dr Tobin.
Dr Tobin said Mr Chauvin and other police officers restricted Mr Floyd’s breathing by flattening his rib cage against the sidewalk and pushing his cuffed hands into his chest, and placing Mr. Chauvin on his neck and back.
The doctor identified the moment he said Mr. Floyd had shown signs of brain damage, four minutes before Mr. Chauvin lifted his knee from his body.
After two days of sometimes tedious testimony from law enforcement on procedures and policies, jurors seemed mesmerized by Dr. Tobin’s ability to break down complex physiological concepts, sometimes jotting down notes in unison.
Leaning into the microphone, tied slightly askew, Dr Tobin used his hands and elbows to show how people were breathing. He gave anatomy lessons by having jurors palpate their own necks and showed an artist’s rendering of how three officers, including Mr. Chauvin, had been positioned on Mr. Floyd.
He delivered his opinions without any ambivalence, noting that his conclusions were based on “very precise” scientific knowledge like the level of oxygen when someone loses consciousness.
Dr Tobin said he has watched portions of the video evidence hundreds of times. He had calculated what he said was the exact weight Mr. Chauvin had placed on Mr. Floyd’s neck (86.9 pounds), had timed Mr. Floyd’s respiratory rate and marked the instant he had took his last breath: 8:25:15 p.m.
He reassured jurors that many of the medical terms they heard during the trial – hypoxia, asphyxia, anoxia – all mean essentially the same thing, “an extremely low oxygen level.”
His testimony may help prosecutors get over the fact that the official autopsy report did not use the word “asphyxia” and seemed to render unnecessary the exact position of Mr. Chauvin’s knees, which has been repeatedly raised.
“I don’t think I have seen an expert witness as effective as this,” said Mary Moriarty, the former Hennepin County chief defender, who followed the televised trial. “He seems to be the world’s foremost expert on the subject, and he explained everything in English, in layman’s terms.
The jury heard repeatedly that the police learned that it was dangerous to hold people face down. Dr Tobin told the jury exactly why, first explaining that just lying down reduces lung capacity.
On top of that, a knee on his neck compressed Mr. Floyd’s airways, he said, and the weight on his back alone made it three times harder to breathe than normal.
Dr Tobin dismissed the oft-repeated adage that someone who can talk can breathe, calling it a “very dangerous mantra to have out there.”
It’s technically true, he said, but “it gives you a huge false sense of security. Granted, the moment you speak you are breathing, but that doesn’t tell you that you are going to breathe five seconds later.
Using video stills, Dr Tobin showed the efforts Mr Floyd had made to free his chest enough to breathe, trying to use his shoulder, fingertips and even his face, crushed flat against the sidewalk, as a lever against Mr. Chauvin’s weight.
He pointed to the tip of Mr. Chauvin’s boot lifted off the curb and the telltale kick of Mr. Floyd’s legs which he said indicated he suffered a brain injury 5 minutes and 3 seconds after Mr. Chauvin placed his knee for the first time. on Mr. Floyd’s neck.
The lawsuit used Dr. Tobin to preemptively pierce the defense argument that Mr. Floyd’s death was caused by his use of fentanyl, underlying heart disease and other physical ailments.
“A healthy person subjected to what Mr. Floyd was subjected to would have died,” said Dr Tobin.
Dr Tobin was born in rural Ireland, attended Dublin medical school and spoke with a sweet Irish touch. He is a pulmonary and critical care physician at Edward Hines Jr. VA Hospital and Loyola University Medical Center in the Chicago area and has practiced for over 40 years, but this was his first time. he was testifying in a criminal case.
He said he has testified several times in medical malpractice cases and waived his usual fee of $ 500 per hour for the Chauvin trial.
Experts say working for free could cut two ways, either impressing the jury or suggesting the witness was biased in favor of one party. Mr. Chauvin’s lawyer, Eric J. Nelson, attempted to highlight the latter possibility. “Have you agreed to waive your hourly rate for this period?” He asked. “You thought that was an important case, didn’t you?”
Dr Tobin disputed the defense’s claim that a high level of carbon dioxide found in Mr Floyd’s blood was the result of consuming fentanyl, instead attributing it to the length of time he was not breathing. not before receiving artificial respiration in an ambulance.
He said if the fentanyl had had a significant effect Mr. Floyd’s breathing rate would have been slower than normal and if Mr. Floyd’s heart disease had been severe it would have been faster. Instead, the rate was normal, he said.
Mr. Nelson pushed back, continuing to make his point that Mr. Floyd’s death could have been an overdose.
He asked if Mr. Floyd’s breathing could have been inhibited if he had taken fentanyl in the moments before the police took him to the ground. Dr Tobin agreed it could have been, but said Mr Floyd never went into a coma, as he would have if he had overdosed.
The prosecution called two other witnesses Thursday who denied the claim that Mr. Floyd died of an overdose. Daniel Isenschmid, a forensic toxicologist at NMS Labs in Pennsylvania, where Mr. Floyd’s blood was tested, said the level of fentanyl in his system was far from clearly fatal. He said it was common for intoxicated drivers who had consumed fentanyl and survived to have an even higher drug concentration than that found in Mr. Floyd’s blood.
Dr William Smock, the police surgeon for the Louisville Metro Police Department and professor of emergency medicine at the University of Louisville School of Medicine, said Mr Floyd would have been much more depressed if he he had overdosed on fentanyl. “He’s breathing. He speaks. He doesn’t snore, ”said Dr Smock.
“He said, ‘Please get off of me please. I want to breathe. I can not breathe. It is not an overdose of fentanyl. It is someone who begs to breathe.
Reporting was contributed by Nicholas Bogel-Burroughs and Tim arango from Minneapolis, John eligon from Kansas City, Missouri, and Sheri fink and Haley willis from New York.