Lack of oxygen resulted in brain damage and caused his heart to stop, the witness said.
Tobin analyzed a graphical presentation of the three officers who detained Floyd for what prosecutors say was nearly 9 1/2 minutes, testifying that Chauvin’s knees were “almost on his neck” for more than 90% of the time.
He cited several other factors that he said also made it difficult for Floyd to breathe: officers lifting up on the suspect’s handcuffs, the hard surface on the street, his inclined position, his turned head and a knee on his back.
Chauvin kept his knee on Floyd̵
When prosecutors repeatedly played a video clip of Floyd on the ground, Tobin pointed to what he saw as a change in the man’s face that told him Floyd was dead. That moment happened about five minutes after Floyd was first attached.
“In the beginning, you can see that he is conscious, you can see light flicker, and then it disappears,” Tobin said. He explained: “This is the moment life goes out of his body.”
Chauvin, 45, is charged with manslaughter and manslaughter in Floyd’s death on May 25. Floyd was arrested outside a neighborhood market after being charged with attempting to pass a $ 20 counterfeit bill.
Spectator video of Floyd crying he could not breathe as spectators shouted for Chauvin to get off him, sparked protests and spread violence around the United States
Defense attorney Eric Nelson has claimed that the now fired white officer did what he was trained to do and that Floyd’s death was caused by illegal drugs and underlying medical problems that included high blood pressure and heart disease. An autopsy found fentanyl and methamphetamine in his body.
But Tobin said he analyzed Floyd’s breathing as seen on body camera video and explained that while fentanyl typically reduces respiratory rate by 40 percent, Floyd’s breathing was “just about normal” just before he lost consciousness. Similarly, he said that people with severe heart disease have very high respiratory rates.
Tobin also said the high level of carbon dioxide measured in the hospital’s emergency room could be explained by the fact that Floyd did not breathe for nearly 10 minutes before paramedics began artificial respiration, as opposed to his breathing being suppressed by fentanyl.
The doctor explained that just because Floyd was talking and turned out to be moving on video does not mean he was breathing enough. He said a leg movement seen in the video was involuntary. And he said a person can continue talking until the airway narrows to 15%, after which “you are in deep trouble.”
Officers can be heard on video telling Floyd that if he can speak, he can breathe.
At cross-examination, Nelson Tobin pressed on the common misconception, pointing to previous testimony that Minneapolis officers are trained that if people can talk, they can breathe.
Nelson also suggested to Tobin that fentanyl in street medicine could affect humans differently than legally obtained fentanyl. He also asked about methamphetamine and noted that there are few reasons why it is legally prescribed. Tobin agreed that it would increase heart rate, but said it would not affect respiratory rate.
Tobin used a simple language with terms like “pump handle” and “bucket handle” to describe the action of breathing. He explained that when the airways narrow, breathing becomes “enormously more difficult” – like “breathing through a straw”.
At one point, the doctor loosened the tie and placed his hands on his own neck and on the back of his head to demonstrate how the airways work, urging jurors to examine their own necks. Most of them did, though the judge later told them not to.
The expert calculated that half of Chauvin’s body weight with his equipment included – or 91.5 pounds – was at times when Chauvin was in an almost vertical position with his toes off the ground, directly on Floyd’s neck.
He said it looked like Floyd was getting enough oxygen to keep his brain alive for the first five minutes because he was still talking. Tobin said that where Chauvin had his knee after five minutes duration was not so important, because by that time Floyd had already experienced brain damage.
Chauvin’s lawyer has repeatedly shown the jury stills from the video, which he said showed Chauvin’s knee was on Floyd’s shoulder blade. But almost all of these photos were taken after the five-minute marking according to the timestamps.