George Floyd died from a low level of oxygen that damaged his brain and caused his heart to stop, a medical expert testified Thursday in the trial of Derek Chauvin, the fired Minneapolis officer charged in Floyd’s death. Dr. Martin Tobin, an expert who specializes in pulmonology and critical care, was the first witness called to the stand on the ninth day of the trial.
Tobin, a Chicago-based physician who is a renowned expert in medical issues involving the lungs and respiratory system, testified that Floyd’s “shallow breaths weren’t able to carry air through his lungs, down to the essential areas of the lungs that get oxygen into the blood and get rid of carbon dioxide.”
Tobin said the weight from officers forcing Floyd’s left wrist high into his chest and an officer’s knee on his left side, in addition to the pressure from the street on the other side of Floyd’s body, acted like a “vise” and constricted his left lung from expanding. Floyd was trying to use his right hand to push up the right side of his body in order to take in air on the right side, “literally trying to breathe with his fingers and knuckles,” Tobin said.
At the same time, Chauvin’s knee on Floyd’s neck was at various points putting pressure on Floyd’s hypopharynx, a small area at the bottom part of the throat, further compromising his breathing, Tobin said. Chauvin kept his knee on Floyd’s neck for three minutes and 27 seconds after Floyd took his last breath, Tobin testified, well after there was “not an ounce of oxygen left in his body.”
Tobin discounted the defense’s suggestion that Floyd’s underlying heart conditions and fentanyl use contributed to his death.
“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.
His testimony on Floyd’s cause of death follows evidence presented Wednesday about Floyd’s drug use. A forensic scientist testified that she found Floyd’s blood and pills with Floyd’s DNA on them in the squad car where he struggled with officers.
The testimony is significant because Floyd’s cause of death has been a key point of dispute at the trial. The defense has suggested Floyd, who suffered from heart disease, died of a heart arrhythmia brought on by drugs he ingested. The prosecution argues Floyd died of oxygen deprivation from being pinned down under Chauvin’s knee.
Chauvin, who was seen in disturbing videos kneeling on Floyd’s neck for more than nine minutes, is charged with second-degree murder,and second-degree manslaughter.
Chauvin has pleaded not guilty. The other three officers involved are charged with aiding and abetting, and are expected to be tried jointly in August.