Doctors: George Floyd died from lack of oxygen

A lung and critical care specialist said Thursday that George Floyd died from a lack of oxygen after former Minneapolis police officer Derek Chauvin pinned him down.

Dr. Martin Tobin of the Edward Hines Jr. Veterans Affairs Hospital and the Loyola University medical school in Illinois told the jury in Chauvin's murder trial that Floyd's breathing was compromised while Chauvin kneeled on the back of his neck for several minutes. Tobin said the pressure from Chauvin's knee, as well as the hard surface on the street, Floyd's prone position and another officer's knee on his back made it difficult for Floyd to breathe.

Tobin said the lack of oxygen resulted in brain damage and caused Floyd's heart to stop. Tobin added that the elevated levels of carbon dioxide found in Floyd's blood were because Floyd could not breathe for nearly 10 minutes before paramedics began artificial respiration.

While examining video of the Chauvin's attempted arrest of Floyd, Tobin said, "at the beginning, you can see he's [Floyd] conscious, you can see slight flickering, and then it disappears." He added, "That's the moment the life goes out of his body."

If you can talk, you can breathe

Chauvin's lead attorney Eric Nelson said that officers could hear Floyd, a 46-year-old Black man, talking, meaning that Floyd could still breathe. Nelson pointed to earlier testimony that Minneapolis officers are trained that if people can speak, they can breathe. Tobin said in his testimony that people can speak until the airway narrows to 15% capacity, after which "you are in deep trouble."

Chauvin, a 45-year-old white man, was charged with the murder and manslaughter of Floyd after videos surfaced of Chauvin and other officers pinning Floyd down while attempting an arrest. Floyd was accused of attempting a purchase with a counterfeit $20 bill. The video sparked protests against police brutality around the United States and the world.

Fentanyl not an issue

The defense had claimed that an autopsy on Floyd revealed fentanyl and methamphetamine in his system. They claimed that increased levels of fentanyl, an opioid commonly found in pain medication, but abused in the ongoing opioid epidemic in the US, could have led to Floyd's death.

Forensic Toxicologist Dr. Daniel Isenschmid of NMS Labs told the court that Floyd had relatively low levels of fentanyl, and that he did not believe that an overdose led to his death. The doctor said he had examined the toxicology reports of more than 2,000 people arrested for driving under the influence of drugs. Dozens of those samples had higher fentanyl quantities than Floyd in their bodies and lived.

On cross-examination, Chauvin's attorney suggested there was no real way to know how much fentanyl Floyd had ingested and Isenschmid agreed.

Tobin also rejected the defense's claim that drugs could have caused Floyd's death. He said a fentanyl overdose would have shown a sharp decrease in the frequency of breaths. Tobin said Floyd did not decrease his breathing until he lost consciousness.

"A healthy person subjected to what Mr. Floyd was subjected to would have died," said Tobin. Dr. William Smock, an emergency and forensic medicine expert who works with police, agreed with Tobin.

"He [Floyd] is saying: 'Please, please. Get off of me, I want to breathe, I can't breathe.' That is not a fentanyl overdose, that is somebody begging to breathe," said Smock.

kbd/sms (AP, AFP, Retuers)