Explainer: Why 'excited delirium' came up at the Chauvin trial

A woman sits behind a desk.
Minneapolis police officer Nicole Mackenzie, the medical support coordinator for the department, which trains officers in first aid, answers questions during the trial of ex-officer Derek Chauvin on April 6. Defense attorney Eric Nelson asked Mackenzie what excited delirium is and how officers are trained to recognize and respond to it.
Screenshot of Court TV video

Updated: April 19, 1:44 p.m. | Posted: April 7, 7:51 a.m.

The attorney for the former Minneapolis police officer accused of murder and manslaughter in George Floyd ’s death cited the disputed concept of excited delirium during closing arguments Monday in an effort to show that the force Derek Chauvin used was objectively reasonable given Floyd's resistance.

Floyd, a 46-year-old Black man, was arrested outside a neighborhood market on May 25, accused of trying to pass a counterfeit $20 bill. A panicky-sounding Floyd struggled and said he was claustrophobic as police tried to shove him into a squad car. After three officers pinned Floyd to the ground, Thomas Lane, a rookie officer at the scene, can be heard on body camera video asking whether he might be experiencing excited delirium.

Meanwhile, Chauvin pressed his knee to Floyd’s neck for about 9 1/2 minutes, even as Floyd struggled, said he couldn’t breathe and eventually became limp.

“Mr. Floyd was able to overcome the efforts of three police officers while handcuffed with his legs and his body strength,” said Chauvin's defense attorney, Eric Nelson, showing body-camera video of the struggle.

He argued that Chauvin, acting as a “reasonable police officer,” was watching for signs of excited delirium.

How has excited delirium come up?

Nelson last week recalled Nicole Mackenzie, a Minneapolis police officer who trains other officers in medical care and who had already testified for the prosecution.

Mackenzie told the jury that new officers are taught how to recognize signs of excited delirium. Suspects may be incoherent, she said, exhibit extraordinary strength, sweat or suffer from abnormal body temperature, or seem like they suddenly snapped. They're taught that cardiovascular disease, drug abuse or mental illness can trigger excited delirium, she said.

But she told the jury that she would defer to an emergency room doctor in diagnosing the condition and she didn't know if Chauvin had received that training, which typically is provided for rookies.

In closings Monday, prosecutor Steve Schleicher said Floyd had not exhibited any of those recognized signs.

“There’s no superhuman strength,” Schleicher told the jury. "There are no super humans, impervious to pain. Nonsense. You heard him. You saw him. He was not impervious to pain. It’s nonsense.”

Why does it matter?

A key question at Chauvin's trial is whether he used reasonable force in pinning Floyd to the pavement for more than nine minutes. Police Department officials have testified that he did not — that Floyd was under control and that force should have quickly ended.

Nelson emphasized that Floyd was bigger than Chauvin, suggested that suspects can present a danger even when handcuffed, and that handcuffs can fail. He also suggested that Chauvin was rightly concerned about angry onlookers. A defense use-of-force expert, Barry Brodd, a former Santa Rosa, Calif., police officer, testified that Chauvin was justified in pinning Floyd to the ground because of his frantic resistance.

What does science say about ‘excited delirium’?

Some coroners in recent decades have attributed in-custody deaths to excited delirium, often in cases where the person had become extremely agitated after taking drugs, having a mental health episode or health problem. But there is no universally accepted definition of it and researchers have said it's not well understood.

The American Psychiatric Association's diagnostic handbook doesn't list it. And one study last year concluded it is mostly cited as a cause only when the person who died had been restrained.

Early in the trial, Dr. Bill Smock — an expert in forensic medicine who works as a police surgeon for the Louisville Metro Police Department in Kentucky and as a professor of emergency medicine at the University of Louisville — testified that he believes excited delirium is real. But he said Floyd met none of the 10 criteria developed by the American College of Emergency Physicians. A minimum of six signs are required for the diagnosis, he said.

A medical examiner in New York concluded that Daniel Prude was in a state of excited delirium when police in Rochester put a hood over his head and pressed his body against the pavement in 2020. State Attorney General Letitia James issued a report recommending that officers be trained to recognize the symptoms of excited delirium.

Elijah McClain — a Black man put in a stranglehold by officers in Aurora, Colo., in 2019 — was injected with ketamine after first responders said he was experiencing excited delirium. He wound up on life support and later died.

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