“It caused damage to his brain that we see, and it also caused a PEA arrhythmia that made his heart stop,” testified Dr. Martin Tobin of Chicago, referring to pulseless electrical activity, a type of cardiac arrest.
“The reason for the low oxygen level was shallow breathing,” he added. “Small breaths. Small tidal volumes. Shallow breaths that failed to carry air through his lungs to the major parts of his lungs, which get oxygen into the blood and get rid of carbon dioxide.”
He identified four main reasons why Floyd died: the handcuffs and the street acting as a “vice,” Chauvin’s left knee on his neck, Floyd̵
The doctor highlighted several still images of police footage showing Floyd pressing his knuckles against the team’s tire, pressing his knuckles to the ground, raising his right shoulder, and even digging his face in the street. These images show Floyd using all possible means to try to lift his chest and breathe, Tobin said.
“It’s a very bad way to breathe. But that’s what you have to do when everything else fails,” he said.
Chauvin’s knee was on Floyd’s neck more than 90 percent of the time, Tobin said. The doctor estimated that this was about 91.5 pounds on Floyd’s neck when his legs fell off the ground.
With the behavior of a kind old professor, Tobin speaks directly to the jury and encourages them to feel parts of their own neck and chest as he describes how breathing works. Almost all the jurors did what the doctor asked, according to a report from the courtroom group.
Tobin’s testimony came on the ninth day of the trial, when prosecutors moved on to the third phase of their case, focusing on a medical analysis of the cause of Floyd’s death.
The first week of the trial focused on the last moments of Floyd on May 25, 2020, in particular the torturous passer-by and the footage from the TV camera that showed his last breaths. Over the past few days, a series of police experts and training coordinators have testified that Chauvin violated police policy and used excessive force on Floyd.
The most important medical evidence is likely to come on Friday, when Hennepin County Chief Medical Expert Dr. Andrew Baker is expected to testify. Baker performed Floyd’s autopsy and determined that his death was murder, listing the cause of death as “cardiac and pulmonary arrest, complicating law enforcement, restraint and neck compression.”
Medical analysis is important to the accusation that Floyd died because Chauvin placed his body weight on Floyd’s neck and back for more than nine minutes – causing death from “positional asphyxia.” Chauvin defender Eric Nelson claims that Floyd died of a drug overdose and previous health conditions.
Chauvin, 45, pleaded not guilty to second-degree murder, third-degree murder and third-degree manslaughter. The trial, which is now the second full week of testimony, is expected to last about a month.
Suspected drug use by Floyd
Senior Special Agent James Reyrson was shown a clip from a Minneapolis police camera footage of Floyd saying while handcuffed and lying on the ground. He initially agreed with Chauvin’s lawyer that it sounded like Floyd said, “I ate too many drugs.”
After a short break, the prosecution released a longer video for Reyerson than the video. Then Reyrson changed his mind. “I believe Mr. Floyd said, ‘I don’t do drugs,'” he said.
Earlier on Wednesday, a Los Angeles Police Department expert hired by the prosecution testified that Chauvin used excessive and deadly force against Floyd when he was not needed.
In addition, several white pills containing fentanyl and methamphetamine were found in Floyd’s vehicle, and a smaller pill with Floyd’s saliva at the back of the police squad, three forensic scientists said on Wednesday.
BCA’s Mackenzie Anderson investigated the vehicles involved in May and then again months later after initially failing to collect some of the pills.
Inside the police car, she initially found Floyd’s shoes and leash and noticed eight bloodstains that matched Floyd’s DNA. During her second search of the car, she found a pill with a rough texture that did not look whole, as well as a few small pieces that she thought might be fragments of pills. Tests have confirmed that the smaller pill has Floyd’s saliva, she testified.
Breahna Giles, a BCA forensic scientist, testified that she analyzed white pills. They had the label of a pill that would contain oxycodone and acetaminophen, but when tested, they did contain methamphetamine and fentanyl, she said.
In addition, a glass tube extracted from the vehicle contained THC, the psychoactive component of marijuana, but not plant material, Giles told the court.