MINNEAPOLIS — A former Hennepin County medical examiner testifying in the murder trial of Derek Chauvin said George Floyd died from asphyxia, or low oxygen, due to officers’ restraint – going a step further than the autopsy that ruled Floyd’s death a homicide last year.
“This is a death where both heart and lungs stop working. The point is it’s due to law enforcement subdual, restraint and compression,” Dr. Lindsey Thomas, who was testifying for the prosecution, said Friday.
Thomas trained Hennepin County’s current chief medical examiner, Dr. Andrew Baker, who ruled Floyd’s death a homicide. In his autopsy report, Baker said Floyd’s heart and lungs stopped amid “law enforcement subdual, restraint and neck compression,” but he did not use the word “asphyxia.”
A family-commissioned autopsy released around the same time found Floyd’s death was a homicide caused by “asphyxiation from sustained pressure.”
Baker was expected to take the witness stand Friday. His testimony will be key to prosecutors, who say Floyd was killed by Chauvin’s knee on his neck for more than nine minutes. The defense argues Floyd died as a result of the drugs in his system and underlying medical issues.
Chauvin is charged with second-degree murder, third-degree murder and second-degree manslaughter in Floyd’s death.
Where things stand: This week, the prosecution has called experts and police officials to testify about proper use of force and medical professionals to testify about how Floyd died. Prosecutors have also asked experts to testify about the role of drugs found in Floyd’s system, trying to head off the defense’s argument that drugs played a key role in his death. The defense has highlighted the effect meth and fentanyl may have on the heart and lungs. The defense has also argued the crowd of bystanders gathered near the scene distracted and threatened the officers, preventing them from giving care to Floyd and meriting additional force.
- Andrew Baker, the chief medical examiner for Hennepin County who conducted the autopsy on George Floyd, took the stand Friday afternoon.
- Jurors have heard from 35 witnesses so far – all called by the prosecution.
- A medical expert in the physiology of breathing said Thursday the way Floyd was restrained prevented him from breathing properly and caused his death.
- Another, a police surgeon, said Floyd didn’t overdose or have a heart attack.
- A forensic toxicologist who analyzed George Floyd’s blood and urine told jurors Thursday the amount of meth in Floyd’s system was consistent with a prescribed dose – a “very low” amount.
Friday morning, the prosecution called forensic pathologist Dr. Lindsey Thomas as an expert witness who has reviewed documents and videos in the case. She also trained Dr. Andrew Baker, the Hennepin County chief medical examiner who ruled Floyd’s death a homicide, and who was expected to testify later on Friday.
Thomas said she agreed with Baker’s autopsy findings. “In this case, I believe the primary mechanism of death is asphyxia, or low oxygen,” she said. “This is not a sudden cardiac death.”
Thomas entered semi-retirement in 2017 but still does consulting and works in the medical examiner’s offices in Reno and Las Vegas. Previously, she was the medical examiner for several Minnesota counties. She said she’s performed about 5,000 autopsies and has consulted with other medical examiners on roughly 1,000 more autopsies.
Thomas said Floyd’s autopsy was “really great for ruling things out.” She said there was no evidence from the autopsy that Floyd had sufficient lung disease to impair his breathing. He didn’t have a heart attack or a stroke, she said. And the slow nature of Floyd’s death shows he did not die of a methamphetamine or fentanyl overdose, she said.
“Basically, Mr. Floyd was in a position … where he was unable to get enough oxygen,” Thomas said, echoing prior testimony by Dr. Martin Tobin and Dr. Bill Smock, other medical expert witnesses called by the prosecution on Thursday. Answering prosecutor Jerry Blackwell, she later emphasized: “There’s no evidence to suggest he would have died that night except for the interactions with law enforcement.”
The long struggle with police produced chemical reactions in Floyd’s body that caused physiological stress, Thomas said: “This goes on for minute, after minute, for nine minutes,” she said. The physiological stress that results from that situation doesn’t show up in an autopsy, but could be considered a contributing cause of death,” Thomas testified.
On cross examination, lead defense attorney Eric Nelson suggested Floyd’s underlying heart issues and drug use contributed to his death.
Prompted by Nelson, Thomas said the autopsy showed Floyd’s heart was enlarged and that Floyd had narrowing of coronary arteries. If Floyd had died at home, with no confrontation with police, Thomas said she would probably have concluded that Floyd died of heart disease.
Asked if, in another hypothetical scenario where Floyd was found dead at home, she would conclude Floyd died of an overdose, Thomas said she “could consider” it.
Nelson also referenced studies in Canada that found people arrested in the prone position did not die. Thomas appeared skeptical of the study. She said the prone position is not inherently dangerous “unless there are other factors.”
“I could be laying by the pool in Florida, on my stomach in the prone position, not inherently dangerous?” Nelson said. “Right,” said Thomas.
When prosecutor Jerry Black re-questioned Thomas, he challenged the hypothetical scenarios Nelson had . “Aren’t those questions a lot like asking, Mrs. Lincoln, if we take John Wilkes Booth out of this,” Blackwell began, only to be stopped by Judge Peter Cahill for posing an argumentative question. Thomas agreed, as a forensic pathologist, she would not pursue a hypothetical situation by removing factors that she concluded had caused death.
Blackwell also followed up on Nelson’s pool scenario. “George Floyd was not laying by the pool on his stomach in Florida, was he?” Blackwell asked. “No,” Thomas said.
Dr. Martin Tobin, a physician who has been working in respiratory physiology for 40 years, testified Thursday that Floyd died from a “low level of oxygen,” which caused damage to his brain and an abnormal heartbeat. Tobin was called as an expert witness by prosecutors and examined records and video in the Floyd case, but he did not conduct an examination of Floyd’s body.
Tobin said he watched videos of Floyd’s arrests “hundreds of times” and found Chauvin’s left knee was on Floyd’s neck for the majority of the time. The combination of Floyd being handcuffed behind his back, the officers’ manipulation of the cuffs, and the pavement beneath Floyd combined to interfere with Floyd’s ability to breathe, Tobin testified.
The overall effect of the restraint was almost “as if a surgeon had gone in and removed the lung,” he said, referring to Floyd’s left lung. “A healthy person subjected to what Mr. Floyd was subjected to would have died as a result of what he was subjected to,” Tobin said. Read more about his testimony here.