Medical examiner says police use of force was factor in George Floyd’s death

The medical examiner of Hennepin County told a US jury on Friday that George Floyd died when the physical force used during his arrest in Minneapolis was more than his strained heart could endure.

Dr Andrew Baker, who performed the official autopsy on Floyd, is a key witness in the trial of former Minneapolis police officer Derek Chauvin. His testimony gave both legal teams fodder as they continue to wrangle over the exact medical circumstances of Floyd’s death.

Chauvin is charged with second- and third-degree murder, and manslaughter, for kneeling on Floyd’s neck for about nine minutes while the 46-year-old said repeatedly that he could not breathe. A bystander filmed the incident and posted it online, sparking worldwide protests calling for racial justice. Chauvin has pleaded not guilty.

Before Baker’s testimony, prosecutors called three medical experts to the stand who said Floyd died of asphyxia — a lack of oxygen. The defence said during opening statements that Floyd died of a cardiac arrhythmia, or irregular heartbeat, combined with his ingestion of fentanyl and methamphetamine.

The death certificate, which Baker filled out, gave Floyd’s cause of death as “cardiopulmonary arrest complicating law enforcement subdual, restraint and neck compression”.

“He had very severe underlying heart disease,” Baker said. “He has a heart that needs more oxygen by virtue of its size, and it’s limited in its ability to step up and provide more oxygen on demand.”

The kind of altercation that occurred between Floyd and Chauvin, Baker said, causes adrenaline and other stress hormones to pour into the body, pushing the heart to beat faster to supply more oxygen.

“In my opinion, the law enforcement subdual, restraint and neck compression was just more than Mr Floyd could take by virtue of those heart conditions,” he said.

Baker said he intentionally did not watch the video before beginning the exam because he did not want it to influence his impressions.

But Baker also testified that he could have, but did not, rule that Floyd’s manner of death was “natural” or an “accident”. Instead, he ruled it a homicide. For a medical examiner, it does not imply criminal culpability, but it does mean “death at the hands of another”.

He also noted that while fentanyl and methamphetamine contributed to Floyd’s death, they were not direct causes of it.

Eric Nelson, Chauvin’s attorney, asked Baker during cross-examination if, after the autopsy, he said to the chief prosecutor in Hennepin county, where Minneapolis is located, that “under different circumstances you would have determined this to be a fentanyl overdose”.

“I don’t recall specifically what I told the county attorney, but it almost certainly went something like this: had Mr Floyd been home alone in his locked residence with no evidence of trauma and the only autopsy finding was that fentanyl level, then yes, I would have established fentanyl toxicity,” Baker replied.

But interpreting toxicology results depends on context, he said, and “it was the stress of that interaction [with law enforcement] that tipped him over the edge given his underlying heart disease and his toxicological status”.

Earlier in the day the prosecution called Dr Lindsey Thomas to the stand to testify that Floyd died from asphyxia due to the force police used to restrain him. Thomas, a former Hennepin County medical examiner who helped train Baker, said that “there’s no evidence to suggest he would have died that night except for the interactions with law enforcement”.