Video: Forensic Pathologist Says George Floyd Died From Lack Of Oxygen

Dr. Andrew Baker, the Hennepin County medical examiner, is expected to testify in a Minneapolis courtroom Friday, as prosecutors try to prove former Minneapolis police officer Derek Chauvin was responsible for George Floyd's death in police custody last May.

Before Baker testifies, the court heard from forensic pathologist Dr. Lindsey Thomas. She is appearing as an expert for the prosecution, but she says she is not being paid to testify.

"I've never had a case like this," she said, where a person's death is so thoroughly documented – mainly through videos from the scene.

When asked if she formed an opinion on "the mechanism" of Floyd's death, Thomas said she has.

"In this case, I believe the primary mechanism of death is asphyxia or low oxygen," she told the jury.

The Hennepin County medical examiner's office ruled last summer that Floyd's death was a homicide, saying his heart and lungs stopped functioning "while being restrained" by police. But it also noted "other significant conditions," including fentanyl intoxication and recent methamphetamine use as well as heart disease.

Chauvin's defense attorney, Eric Nelson, has said Floyd's heart condition was also to blame for his death. Nelson has also said Floyd may have been overdosing on drugs when he died, airing the theory that Floyd put drugs in his mouth when police approached him.

Under questioning from Nelson, Thomas said she would consider Floyd's heart to be "slightly enlarged," but she added that by some measures, his heart would not be considered to be enlarged.

High blood pressure is the primary cause of an enlarged heart, Thomas said. She also confirmed that Floyd had a history of high blood pressure.

On Thursday, pulmonary specialist Dr. Martin Tobin told the jury that Floyd died from a lack of oxygen that caused brain damage after the first five minutes of the police officers' restraint of Floyd.

Tobin also said that fentanyl did not play a role, citing Floyd's normal breathing rate. It would have been much slower, he said, if Floyd was under the effects of fentanyl.

Thomas worked for years in the Hennepin County medical examiner's office, and also worked for or led similar agencies in Minnesota. She's now semi-retired, she said, but works part-time in medical examiner's offices in Reno, Nev., and Salt Lake City. She is licensed in several states and has performed thousands of autopsies. She and Baker are friends and former colleagues, she said.

Chauvin is charged with three criminal counts: second-degree murder — unintentional — while committing a felony; third-degree murder — perpetrating eminently dangerous act and evincing depraved mind; and second-degree manslaughter — culpable negligence creating unreasonable risk.

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