*Two medical doctors and a forensic toxicologist testified Thursday in Derek Chauvin’s murder trial in the death of George Floyd.
The doctors testified that Floyd died of a lack of oxygen by being pinned to the ground with his hands cuffed behind him and Chauvin’s knee on his neck. Dr. Martin Tobin, a world-renowned expert on breathing, illustrated how Floyd’s use of his knuckles and fingers to try and push his body off the pavement so he could breathe is a sign of oxygen levels in the body being depleted.
Tobin said Floyd died from a low level of oxygen, “and this caused damage to his brain that we see, and it also caused a PEA (pulseless electrical activity) arrhythmia because his heart stopped. Below, he uses a video to simulate how Floyd couldn’t breathe.
Dr. Daniel Isenschmid, a forensic toxicologist, testified that Floyd died of positional asphyxia, “which is a fancy way of saying he died because he had no oxygen left in his body,” Isenschmid said. “When the body is deprived of oxygen, in this case from pressure on his chest and back, he gradually succumbed to lower and lower levels of oxygen until it was gone and he died.”
Isenschmid said that he came to that conclusion after ruling out other causes of death, including fentanyl overdose. He also told jurors that the amount of methamphetamine that the lab he works for found in Floyd’s blood and urine would not have been sufficient to cause intoxication.
Below, Isenschmid said the idea that Floyd experienced “excited delirium” at the time of his arrest he also does not align with indicators gleaned from footage of his last moments, according to Smock. He was not behaving in an agitated manner, was not sweating profusely and was not breathing rapidly, Smock said for example.
On Thursday afternoon, prosecutors called to the stand emergency medicine physician Dr. William Smock, the police surgeon at the Louisville Metro Police Department and a professor of emergency medicine at the University of Louisville. He also trains police on topics such as strangulation and asphyxia and forensic evaluation of gunshot wounds. He said he’s an expert in asphyxial death and strangulation.
Smock also testified that in video footage, Floyd appeared to be pushing his knuckles against the tire in an attempt to breathe. Smock said Floyd was alert and responding to the pain of being restrained. “He’s breathing. He’s talking. He’s not snoring. He’s saying, ‘please, please get off of me, I can’t breathe.’ That is not a fentanyl overdose. That’s someone begging to breathe.”
Hennepin County Medical Examiner, Dr. Andrew Baker, is expected to testify on Friday. The medical examiner said an autopsy listed Floyd’s cause of death as a “cardiopulmonary arrest complicating law enforcement subdual, restraint, and neck compression.”