George Floyd was killed by lack of oxygen – and not by drugs, Irish doctor tells murder trial

George Floyd died of a lack of oxygen from being pinned to the pavement with a knee on his neck, a medical expert testified at former Officer Derek Chauvin’s murder trial yesterday.

Irish-born Dr Martin Tobin emphatically rejected the defence theory that Mr Floyd’s drug use and underlying health problems were what killed him.

“A healthy person subjected to what Mr Floyd was subjected to would have died,” said prosecution witness Dr Tobin, a lung and critical care specialist.

He told the jury that Mr Floyd’s breathing was severely constricted while Mr Chauvin and two other officers held the 46-year-old black man down on his stomach last May with his hands cuffed behind him and his face jammed against the ground in Minneapolis, Minnesota.

The lack of oxygen resulted in brain damage and caused his heart to stop, Dr Tobin said.

Dr Tobin, analysing a graphic presentation of the three officers restraining Mr Floyd for what prosecutors say was almost nine and a half minutes, testified that Mr Chauvin’s knee was “virtually on the neck” for more than 90pc of the time.

He cited several other factors that he said also made it difficult for Mr Floyd to breathe: officers lifting up on the suspect’s handcuffs, the hard surface of the street, his prone position, his turned head and a knee on his back.

Mr Chauvin kept his knee on Mr Floyd’s neck for three minutes, two seconds, after Mr Floyd had “reached the point where there was not one ounce of oxygen left in the body,” Dr Tobin said.

As prosecutors repeatedly played a video clip of Mr Floyd on the ground, Dr Tobin pinpointed what he saw as a change in the man’s face that told him Mr Floyd was dead.

“At the beginning you can see he’s conscious, you can see slight flickering, and then it disappears,” the witness said. He explained: “That’s the moment the life goes out of his body.”

Mr Chauvin (45) is charged with murder and manslaughter in Mr Floyd’s death May 25. Mr Floyd was arrested outside a neighbourhood market after being accused of trying to pass a counterfeit $20 bill.

Bystander video of Mr Floyd crying that he couldn’t breathe as onlookers yelled at Mr Chauvin to get off him sparked protests and scattered violence around the US.

Eric Nelson, defending, has argued that the now-fired white officer did what he was trained to do and that Mr Floyd’s death was caused by illegal drugs and underlying medical problems that included high blood pressure and heart disease. An post-mortem exam found fentanyl and methamphetamine in his body.

But Dr Tobin said he analysed Mr Floyd’s respiration as seen on body-camera video and explained that while fentanyl typically cuts the rate of respiration by 40pc, Mr Floyd’s breathing was “right around normal” just before he lost consciousness. Similarly, he said people with severe heart disease have very high respiratory rates. Dr Tobin also said the high blood level of carbon dioxide measured in the hospital emergency room can be explained by the fact that Mr Floyd was not breathing for nearly 10 minutes before paramedics began artificial respiration, as opposed to his breathing being suppressed by fentanyl.

The doctor explained that just because Mr Floyd was talking and shown moving on video, it doesn’t mean he was breathing adequately.

He told the jury a person can continue to speak until the airway narrows to 15pc, after which “you are in deep trouble”.

Officers can be heard on video telling Mr Floyd that if he can talk, he can breathe.

Dr Tobin also reviewed video that showed Mr Floyd’s leg moving upward at one point, and he explained that it was involuntary.

The doctor explained that when the airway narrows, breathing becomes “enormously more difficult” – like “breathing through a drinking straw.”

The expert calculated that half of Mr Chauvin’s body weight – six and a half stone– was directly on Mr Floyd’s neck at times.

The trial continues at Hennepin county courthouse.

Online Editors