Baker’s testimony will come on the 10th day of Chauvin’s trial, the culmination of a week filled with expert testimony by not only medical experts, but also policing experts who testified Chauvin violated policy and used excessive force on Floyd. Chauvin has pleaded not guilty to second-degree murder, third-degree murder and third-degree manslaughter charges.
Prosecutors on Friday first called forensic pathologist Dr. Lindsey Thomas, who has worked as a medical examiner herself, including in the Hennepin County Medical Examiner’s Office, and who was part of Baker’s training.
Thomas — who has reviewed various records, including the medical examiner’s autopsy — agreed with Baker’s finding in the cause of death, adding she believed the “primary mechanism of death is asphyxia or low oxygen.”
Because of the restraint and his position, she said, Floyd was “unable to get enough oxygen in” to support his body’s functions.
Thomas explained the technical wording of the medical examiner’s finding in the cause of death, saying, “What it means to me is that the activities of the law enforcement officers resulted in Mr. Floyd’s death. And that specifically those activities were the subdual, the restraint and the neck compression.”
“There’s no evidence,” she later added, “to suggest he would have died that night except for the interactions with law enforcement.”
Thomas said she would not have used the word “asphyxia” in Floyd’s death certificate, saying it does not offer much additional information and requires more explanation. While a death by hanging is a type of asphyxial death, she explained, she wouldn’t say “asphyxia due to hanging” — she’d just say “hanging.”
Additionally, Thomas said her review of the case allowed her to rule out other causes of death, including a drug overdose.
Floyd’s death was not “sudden” like it would be with a methamphetamine overdose, she said. And it was not slow like one would see with fentanyl, where “the death is slow, it’s peaceful, they fall asleep.”
Floyd died from ‘low level of oxygen, ‘doc says
A pulmonary critical care doctor testified Thursday that Floyd died from a “low level of oxygen” when Chauvin pinned him to the street with his knee, restricting Floyd’s ability to breathe.
Dr. Martin Tobin of Chicago identified four main reasons why Floyd died: the handcuffs and the street acting as a “vise;” Chauvin’s left knee on his neck; Floyd’s prone position; and Chauvin’s right knee on Floyd’s back, arm and side. Combined, these limited Floyd’s ability to expand his lungs and narrowed his hypopharynx, a part of the throat that air passes through.
“The cause of the low level of oxygen was shallow breathing,” Tobin said. “Small breaths. Small tidal volumes. Shallow breaths that weren’t able to carry the air through his lungs down to the essential areas of the lungs that get oxygen into the blood and get rid of the carbon dioxide.”
Floyd’s preexisting health conditions and drug use were not relevant to his death, Tobin said.
“A healthy person subjected to what Mr. Floyd was subjected to would have died,” he said.
The medical analysis is important to the prosecution’s case that Chauvin was a substantial cause of Floyd’s death when he put his body weight on Floyd’s neck and back for over nine minutes — causing death by “positional asphyxia.” Chauvin’s defense attorney Eric Nelson has argued that Floyd died of a drug overdose and preexisting health conditions.
Tobin rejected the theory that fentanyl played a role in Floyd’s death, along with Dr. Bill Smock, an emergency medicine physician and police surgeon for the Louisville Metro Police, who also testified Thursday.
People who overdose on fentanyl become listless and stop breathing, while Floyd was desperately trying to breathe, Smock said.
“That is not a fentanyl overdose,” he said. “That is somebody begging to breathe.”
CNN’s Eric Levenson, Aaron Cooper and Brad Parks contributed to this report.