MINNEAPOLIS – The medical examiner who did the autopsy on George Floyd testified Friday that because of underlying heart conditions, his restraint by law enforcement "was just more than Mr. Floyd could take," resulting in his death at the hands of Minneapolis police.
Soon after Floyd's arrest on May 25, Dr. Andrew Baker ruled that Floyd's cause of death in Minneapolis was "cardiopulmonary arrest complicating law enforcement subdual, restraint and neck compression."
Baker did not include a lack of oxygen, or asphyxia, a cause that three medical expert witnesses has firmly said was what killed Floyd after being pinned on his stomach under the ex-police officer Derek Chauvin's knee for more than nine minutes.
Cause of death has provided a sharp divide between the state and the defense. Defense attorney Eric Nelson has argued that Floyd died of a cardiac arrest, illicit drug use and various chronic health problems.
On the whole, Baker said, "To the best of my knowledge he was generally healthy on May 25 before the events of that evening."
That said, the doctor tied in the somewhat diseased condition of the 46-year-old Floyd's heart to his death.
"You know he had very severe underlying heart disease," Baker said. "Mr. Floyd also had what we call hypertensive heart disease, meaning his heart weighed more than it should. So he has a heart that already needs more oxygen than a normal heart by virtue of its size, and it's limited in its ability to step up to provide more oxygen when there's demand because of the narrowing of his coronary arteries.
"Now in the context of an altercation with other people that involves things like physical restraint, it involves things like being held to the ground, it involves things like the pain that you would incur from having your cheek up against the asphalt and that abrasion on your shoulder, those events are gonna cause stress hormones to pour out of your body, specifically things like adrenaline, and what that adrenaline is going to do is it's going to ask your heart to beat faster," Baker testified.
"It's going to ask your body for more oxygen so that you can get through that altercation, and in my opinion, the law enforcement subdual restraint and the neck compression was just more than Mr. Floyd could take by virtue of those heart conditions."
While earlier medical expert testimony doubted that Floyd's physical condition or his illicit drug use played a role in the death, Baker said under questioning by defense attorney Nelson that "in my opinion, yes," they were factors.
Nelson also returned to a line of questioning about bruising on the neck of someone who dies of asphyxia from strangulation.
"In my world, we typically see bruises on the neck and abrasions on the neck," Baker said, who added that he saw no bruises or abrasions on Floyd's neck.
Asked by Nelson about whether Floyd died of asphyxiation, Baker said: "That's something we don't really see, pressure on the back of the neck resulting in strangulation."
"Or asphyxiation?" Nelson asked.
Baker confirmed that's correct.
Baker testified that his autopsy on Floyd's heart revealed no previous damage to the heart muscle by artery blockage from cholesterol and scarring that left them "pretty severely narrowed" that he estimated in some locations at 75% to 90%. Inspection of the brain and lungs also found nothing out of the ordinary.
The doctor began his testimony by saying, "I was aware that Mr. Floyd had become unconscious while he was in police custody" and died at the hospital. He opted not to look at videos of Floyd's death, including the one that went viral online, so as not to be biased in his findings.
Baker then was shown photos he took from the autopsy and also distributed to the jury, others in the courtroom but out of the view of the global livestream audience.
The doctor said one photo showed bruises and scrapes to his left eyebrow area. He said he suffered those injuries while "being pinned against the asphalt the night before."
"In the prone position?" prosecutor Jerry Blackwell said. "Yes," the doctor responded.
Baker then went on to go through other photos of other injuries to Floyd, again repeating the same conclusion about the source of the wounds.
An image of the parallel lines on Floyd's wrists, he said, are "pretty typical of handcuff marks that we see at autopsy."
One of the experts who testified on behalf of the prosecution was Dr. Lindsey Thomas, a veteran medical examiner who worked on Baker's staff from 2013 to 2017 and considers him a friend.
"In this case, I believe the primary mechanism of death is asphyxia, or low oxygen," said Thomas, a medical examiner of 37 years who retired from the Hennepin County Medical Examiner's Office and still works part-time as a forensic pathologist in Reno and Salt Lake City.
Thomas explained that although Floyd's heart stopped, he didn't die from a heart attack.
"The activities of the law enforcement officers resulted in Mr. Floyd's death, and specifically those activities were the subdual restraint and the neck compression," she said.
She said that the sheer volume of videos of Floyd's death was "absolutely unique" in that she'd never had a case so thoroughly documented, and it helped her arrive to determine how Floyd died.
"What I observed from all of these videos is this was not a sudden death," Thomas testified. "It's not like snow shoveling when someone clutches their chest and falls over. There was nothing sudden about his death."
She later said with certainty, "There's no evidence to suggest he would have died that night except for the interactions with law enforcement."
Thomas, who helped train Baker when he was a resident in the office, said she agreed with Baker's determination on the cause of death. However, Thomas's declaration runs counter to Baker's assessment that he could not say whether Floyd would have lived "but for" the officers' use of force, according to documents obtained in the case.
"Baker did not believe that the prone position was any more dangerous than other positions based on an article or journal he had read," said a summary of the meeting.
He also listed hardening and thickening of the artery walls, heart disease and illicit drug use as "other significant conditions." Fentanyl and methamphetamine were also found in Floyd's system, Baker's autopsy results noted.
Thomas also joined other expert witnesses before her saying illicit drug use did not kill Floyd.
Prosecutor Jerry Blackwell spent a fair amount of time having Thomas explain some of the limitations of an autopsy and what advantages she had in her research of Floyd's death.
She zeroed in on why Floyd's health challenges and drug use were included by Baker, whom she considers a friend, and explained that such information is valuable for a "public health purpose" and not considered a direct cause of death.
"In any given case, we aren't just thinking of this particular person," Thomas said. "[Autopsy results] list disease processes or drugs that are present at the time of death, but we don't believe they directly contributed to the cause of death."
She also downplayed the autopsy failing to mention lack of oxygen, or asphyxia, despite she and others who have testified to this being the direct cause of death.
"I tend not to use it," she said, while also pointing out that there is no test during an autopsy to detect this cause. As an example, Thomas said, "I wouldn't say asphyxia during hanging. I would just say hanging."
She revisited ground covered by previous medical expert witnesses concerning injuries on Floyd's body that revealed his struggle to reposition himself to allow him to better breathe: scrapes on his knuckles, face and shoulders, for example.
The judge then had photos of the injuries distributed to the jurors, and Thomas explained what they depicted and why the images "are consistent that he is pushing himself so he can get in a position to breathe."
Thomas testified that she wasn't being paid to serve as an expert. "You reached out to me, and I knew this was going to be important, and I felt like I had something to offer, and I wanted to do what I could to explain what I think happened," she said.
Thomas testified that the bodily stress of being restrained in a prone position must be taken into account and has been absent in controlled research in this area.
"Mr. Floyd was already in a position where he was experiencing breathing and getting enough oxygen in this body," she said. "On top of that, now there's the physiological stress that's putting increased demand on his heart, lungs and muscles. ... He's using his strength to get himself into a position where he can breathe."
Add in the release of adrenaline, rapid breathing and other bodily reactions, she said, "it's kind of a double whammy to his heart, lungs, his muscles and his whole system."
In cross examination by defense attorney Eric Nelson, Thomas acknowledged that Floyd had a slightly enlarged heart that would require more blood and significantly narrowed arteries.
With those factors, along with the stress Floyd endured, "the heart has to work very, very hard in this case, right?" Nelson asked.
"Let's take the police out of this," he continued. "Let's assume you found Mr. Floyd dead in his residence, no police involvement, no drugs, the only thing you found were these facts about his heart. What would you conclude is the cause of death?" Nelson asked.
"In those very narrow circumstances, I would probably conclude that the cause of death was his heart disease," Thomas said.
Nelson revived his earlier questioning of witnesses pointing out to Thomas the lack of bruising on Floyd's neck or elsewhere and how fentanyl and meth can be fatal, even in small amounts. Thomas agreed, but with qualified answers such as "it can" or there being numerous variables to consider.
Nelson said that when someone is in cardiac arrest and given a saline solution intravenously — as occurred in Floyd's case — that procedure can decrease the amount of controlled substances that would be measured in the body.
Thomas called that "a theoretical possibility."
Blackwell rose again and took aim at Nelson's scenario minus the police.
"Aren't those questions a lot like asking, 'Mrs. Lincoln, if we take John Wilkes Booth out of this ...' " before Nelson objected and the judge sustained and explained the incomplete question was argumentative."
Chauvin for the first time had a spectator in the courtroom, an unidentified woman who sat in the family representative seat.
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(Star Tribune staff writers Rochelle Olson, Libor Jany and Chao Xiong contributed to this report.)
