Second physician testifies George Floyd died of asphyxia, not drugs or heart attack

George Floyd died of asphyxia in Minneapolis Police Department custody, not a drug overdose, heart attack or excited delirium, an emergency medicine and toxicology expert testified Wednesday in St. Paul in the federal civil rights trial of three former city officers.

Vik Bebarta, a professor of emergency medicine, toxicology and pharmacology at the University of Colorado in Denver, said Floyd died "from a lack of oxygen to his brain" when he was "suffocated and his airway was closed, he could not breathe."

"When the airway is blocked, you pass out, stop breathing and your heart stops," Bebarta said. He determined the cause by reviewing medical records and watching videos of Floyd before and during police restraint May 25, 2020, in the street outside Cup Foods in south Minneapolis.

Bebarta was the second paid prosecution expert to testify this week that Floyd died of asphyxia because his airway was restricted by former officer Derek Chauvin's knee on his neck for more than nine minutes.

J. Alexander Kueng, Thomas Lane and Tou Thao, the other three former officers on the scene with Chauvin, are on trial accused of failing to provide aid to Floyd while he was in their custody. Thao and Kueng also are charged with failing to intervene in Chauvin's illegal restraint.

Federal prosecutors are trying to show that Floyd died as a direct result of the officers' actions. Through cross-examination, the defense has tried to show that he may have died from a complex and difficult-to-diagnose mix of drugs and pre-existing conditions.

Assistant U.S. Attorney Manda Sertich walked Bebarta through the drugs found in Floyd's system when he died, including methamphetamine and fentanyl. Bebarta said the amounts were too low to have caused his death.

While in the store, Bebarta said, Floyd was alert. "There is no sign that he was showing any signs of an imminent drug overdose," he said.

In contrast, someone "heavily impaired would not laugh or smile or have a conversation," Bebarta said.

He also discussed Floyd's behavior after Lane and Kueng approached him in his vehicle, handcuffed him and walked him across the street. "Folks who have a drug overdose don't stand up and walk," Bebarta said. "They don't recall their date of birth or their name."

The doctor also ruled out a heart attack, saying Floyd wasn't heard complaining of chest pain. Like a Harvard physician earlier this week, Bebarta said Floyd lost consciousness as evidenced by the fact he stopped speaking and his face went slack.

Bebarta also ruled out excited delirium or extreme agitation brought on by methamphetamine as causes of Floyd's death. He said people on high levels of methamphetamine often hear voices, hallucinate and run around naked, but Floyd did none of these things.

Bebarta dismissed the fentanyl in Floyd's blood as a factor in his death. Floyd had 11 nanograms per milliliter of fentanyl in his blood, which Bebarta said is low and below levels used for pain at hospitals. Patients who overdose have 40 nanograms or higher in their blood, he said.

During cross examination, Thao's lawyer Robert Paule focused on excited delirium, which Bebarta also referred to as "agitated delirium."

Bebarta said it's not a diagnosis but a collection of symptoms and something he'd seen often. Paule appeared to be trying to show that the diagnosis is difficult to pinpoint for experienced physicians, let alone police officers on the street.

Paule noted that Bebarta is a highly trained physician with 34 years of experience working 60 to 80 hours a week. "So a police officer's medical knowledge is very, very different from yours," Paule said.

Bebarta said police officers have different training, but they learn basic life support and "have the ability to check a pulse and check for breathing."

Kueng's attorney, Thomas Plunkett, alluded to the pressure the officers were under on the scene, asking Bebarta if he was able to review Floyd's case comfortably with a coffee, soda or snack. Bebarta responded, "I was writing a report, I wasn't taking care of a patient."

Lane's lawyer, Earl Gray, pointed out that Lane was heard on the recording saying he thought Floyd was breathing. Bebata agreed he heard that. Gray also noted that Kueng then checked a pulse and when he couldn't find one, Lane checked for a pulse.

He also pointed to the three-minute time lag between when paramedic Derek Smith arrived on the scene and checked Floyd's carotid artery for a pulse and when chest compressions began in the ambulance. Both physicians this week testified that for every minute of delay in starting CPR after cardiac arrest, a patient's chances of survival decrease by 10%.

Bebarta, an Air Force colonel, testified that he had four combat deployments to Iraq, Afghanistan and Syria. He said he charges $700 an hour to testify.

Late Wednesday, McKenzie Anderson, a forensic scientist and crime scene team leader at the state Bureau of Criminal Apprehension, talked about photographing the crime scene as well as the process of searching both the police squad car and Floyd's Mercedes.