Chauvin’s Defense Faces Uphill Battle After Multiple Experts Testify Floyd Died Of Oxygen Deficiency


Two medical experts—a police surgeon and a renowned pulmonologist—testified on Thursday at Derek Chauvin’s trial that George Floyd died of oxygen deficiency caused by police’s prolonged restraint of him, rebutting, with a strong measure of authority, the key argument of the former Minneapolis police officer’s defense that Floyd died of a drug overdose.

Key Facts

First on the stand was Dr. Martin Tobin, a physician at Hines VA Medical Center in Chicago who served as an unpaid witness for the prosecution, who testified that after reviewing the medical records related to the case, in addition to bystander testimony and video footage, he felt he could conclude with a reasonable degree of certainty that Floyd died of a low level of oxygen as a result of how he was restrained.

During cross-examination, Tobin strongly rejected questions from Chauvin’s defense attorney Eric Nelson about whether the fentanyl found in Floyd’s system caused his oxygen levels to drop, testifying that while the drug can have that effect, neither Floyd’s respiratory rate nor the level of carbon dioxide in his blood supported that conclusion. 

When asked about why the autopsy report from the Hennepin County Medical Examiner’s Office showed no bruises on Floyd’s neck, Tobin explained that he wouldn’t expect bruising because the contact was static: “When I go to church, I sit on a hard bench … I don’t get bruising on my bottom.”

Later in the day, Bill Smock, an emergency medicine physician and police surgeon for the Louisville Metro Police Department who was paid to testify, also said Floyd’s death was due to a lack of oxygen. 

“Mr. Floyd died from positional asphyxia, which is a fancy way of saying he died because he had no oxygen left in his body,” Smock said, citing “pressure on his chest and back” as the cause of the deprivation.

The testimony from the two witnesses on Thursday compounds that of Dr. Bradford Langenfeld, an emergency care doctor who treated Floyd at Hennepin County Medical Center after his arrest, who said he believed Floyd was most likely killed by oxygen deprivation, or “asphyxia.” 

Crucial Quote 

“A healthy person subjected to what George Floyd was subjected to would have died,” said Tobin.

What To Watch For

The defense will have to persuade jurors against this testimony, as well statements from the prosecution’s second witness on Thursday: David Isenschmid, a forensic toxicologist from the lab in Pennsylvania that tested Floyd’s blood. Isenschmid testified that in addition to 11 nanograms per milliliter of fentanyl, NMS Labs found norfentanyl, a metabolized version of the drug, in Floyd’s body at his time of death. Victims of overdoses rarely have norfentanyl in their blood, Isenschmid testified. 

Key Background

Thursday was the ninth day of the trial of Chauvin, a 19-year veteran of the Minneapolis Police Department facing murder and manslaughter charges for Floyd’s death. The trial is expected to stretch through most of April, and has so far focused on the testimony of witnesses called by the prosecution. When it’s the defense’s turn to call witnesses, Nelson said there will be a mix of Minneapolis police officers or department employees, medical personnel, emergency dispatch, experts, and  bystanders. 

Further Reading

“Lung Expert Testifies Floyd Died From Police Restraint—And So Would A ‘Healthy Person’” (Forbes)

“George Floyd Experienced Pain Comparable To Lung Surgery, Expert Testifies” (Forbes)