On the night he died, Spokane, Washington janitor Otto Zehm had grown frustrated with an ATM and screamed.

The behavior of the 36-year-old, who had schizophrenia, frightened a pair of young women who had just finished withdrawing cash on that night in March 2006. They called 911, and minutes later, Zehm was beaten by police, hogtied, and left to suffocate to death on the floor of a nearby convenience store.

When police initially sought to escape blame for Zehm's killing, they floated a controversial medical condition that, more than a decade later, skeptics are increasingly calling a scapegoat for in-custody deaths: "excited delirium."

Doctors who believe it is a true condition aren't precisely sure what starts it or how it works, and the vaguely defined condition isn't recognized by most influential medical groups. Many first responders, prominent emergency doctors and medical examiners say it sends people who have mental illnesses or are under the influence of stimulants into a delusional rage that can end in sudden death, especially when combined with police restraint.

The recent deaths of Elijah McClain in Aurora, Colorado, and Daniel Prude in Rochester, New York, have been attributed by authorities to excited delirium. One of the officers who pinned George Floyd to the ground said he was worried about excited delirium as Floyd cried out that he couldn't breathe.

Federal appellate courts have issued opinions shielding officers from liability in wrongful death cases, saying their forcible restraint of people apparently in the throes of excited delirium — even when against policy — does not remove their qualified immunity.

But many medical and police accountability experts question whether excited delirium is a valid condition at all. Some suggest that it's so poorly defined that it provides a convenient catch-all for sudden deaths in custody or after a violent struggle with police.

Dr. Michael Baden, a New York medical examiner known for investigating some of the highest-profile deaths in modern history, told Law360 that he doesn't believe excited delirium should be considered a valid cause of death. Usually, people are dying of asphyxiation because police restrain them in prone positions — a cause of death that has a long and well-understood history, he said.

"It's just a means of dismissing or whitewashing too much force used by law enforcement," he said. "There's nothing scientific. The concept is: A person dies and you don't find any other cause of death, then it's excited delirium.

"My concern is that it seems to be a boutique diagnosis that's largely used only when somebody dies during restraint by law enforcement."

The History and Anatomy

The recorded history of excited delirium traces back to Dr. Luther Bell, a 19th century psychiatrist who noticed patients at his asylum would sometimes experience an intense manic episode and then die after being restrained. It first became known as "Bell's mania."

Excited delirium became a favored term after an emergency room doctor and a medical examiner from Miami wrote about a series of deaths in Southern Florida in the 1980s. Young men on cocaine became inexplicably paranoid, "followed by bizarre and violent behavior … frequently accompanied by unexpected strength and hyperthermia," they wrote in the July 1985 issue of the Journal of Forensic Sciences. "Fatal respiratory collapse occurred suddenly and without warning, generally within a few minutes to an hour after the victim was restrained. Five of the seven died while in police custody."

The drug concentrations in their blood were 10 times lower than what would be likely to cause a deadly overdose, the doctors wrote. They recommended that patients exhibiting such symptoms be immediately transported to a medical facility.

Medical organizations, however, are split on whether excited delirium is an actual diagnosis.

The World Health Organization, the American Psychological Association and the American Medical Association do not officially recognize it. The American College of Emergency Physicians and the National Association of Medical Examiners, however, do.

No organization keeps track of excited delirium cases or deaths. Swiss researchers in 2017 tried to review available literature about excited delirium, but struggled to find consistent and high-quality records and studies. They and others have noted that there doesn't seem to be a universally recognized definition of the condition, but that it is disproportionately attributed to men and Black people. 

Those who subscribe to excited delirium say it begins with a mysterious change to the brain.

Researchers have theorized it occurs after certain drugs or mental illnesses alter the way the brain handles dopamine, a powerful chemical messenger that helps to regulate motivation, bodily functions, and pleasure and pain.

Dr. Gary Vilke, chief of emergency medicine at the University of California, San Diego Health System, said a person experiencing an episode of excited delirium is practically drowning in dopamine.

The prevailing theory holds that the flood of dopamine causes the brain and central nervous system to kick into high gear, said Vilke, who has studied excited delirium since the mid-1990s and said he has seen many cases in the emergency room.

Vilke and other experts described such cases as follows:

The patient's heart rate and blood pressure increase, they become more active and resistant to fatigue, their body temperature begins to rise as their central nervous system revs up, the brain becomes overstimulated, and the delusions begin.

"A lot of them have delusions of heat or hot things and devils and volcanoes and fires and stuff like that," Vilke said. "They're running around naked, covered in sweat, that's all that physiologic internal combustion type of thing going on."

This neurological overdrive translates into a surge in physical activity. They become physically erratic and possibly violent, flailing their limbs and attacking people and objects.

The muscles, pushed beyond exhaustion, begin to release lactic acid into the bloodstream. When this goes on for too long, it can acidify the blood and lead to an organ-threatening condition called acidosis.

All the while, the heart is beating hard and the person's core temperature is rising over 100 degrees.

All of these problems combine to create a life-threatening condition even on its own, Vilke and other experts said. But experts said that the risk of death rises when the patient is restrained, usually by police.

Uncertainty

Baden has recently reviewed the police killings of Eric Garner, Michael Brown and George Floyd — cases that contributed to the protests of police brutality against Black people that have since swept the globe.

He said that those presumed to be suffering from excited delirium may well be heating up not because of some internal, dopamine-driven combustion, but simply because they're agitated or struggling with officers. Internal temperatures can elevate during arguments or physical activity, he said.

It's troubling, he said, that supposed excited delirium doesn't leave any telltale signs for an autopsy to uncover. That's something it has in common with simple asphyxia, where video evidence might be the only clue that the medical examiner has to go by if the signs on the body don't point to a specific cause of death, he said.

Police bodycam footage has played a role in the investigations of some recent deaths blamed on excited delirium.

Elijah McClain, a 23-year-old Black man, died last year after police wrestled him to the ground and restrained him and paramedics injected him with a heavy dose of the sedative ketamine.

An autopsy report said it was unclear whether police caused his death or he died of natural causes due to excited delirium. McClain had not been previously diagnosed with a mental illness and did not have stimulants in his system, but the report suggested that he may have had an undiagnosed mental condition.

Local prosecutors declined to charge the involved officers, citing uncertainty that the officers caused McClain's death.

Mari Newman, a partner at Killmer Lane & Newman LLP representing McClain's family in litigation against the Aurora Police Department, described the case as horrifying and Orwellian.

"We have a constitutional right to bodily integrity," Newman said. "And this idea that you could just be walking home, not even suspected of having committed a crime, be grabbed and shackled and to be subjected to not just excessive force but torture, and then involuntarily injected with a dangerous drug, that at best is designed to erase your memory and at worst can kill you, is horrifying."

In contrast to many purported cases of excited delirium where experts say the affected overheat and undress, police bodycam footage showed McClain was wearing a ski mask as he walked along the sidewalk and that he responded coherently to officers.

As protests mounted over the young man's death, state and federal officials stepped in to investigate, and the city has hired an independent lawyer to review the matter.

Meanwhile, in the Rochester case, bodycam video showed Daniel Prude meeting officers fully nude in the middle of a wet street under gentle nighttime snowfall in March.

Officers said in the video that Prude, who was Black, had broken a window and tried to pick up a trash can. Prude rambled loudly and nonsensically, drawing chuckles from the officers. They told him to lie down and put his hands behind his back, and he seemed fairly compliant. He remained on the ground, expressing increasing displeasure about the handcuffs, for several minutes and then began to spit.

Officers placed a "spit hood" over his head, expressing concern that he might have COVID-19. Still handcuffed, he sat up and seemed to be trying to get to his feet as he demanded an officer's gun. The officers pinned him, one pushing his head and neck into the ground and another putting a knee on his back. Prude began to gurgle and grow quiet as paramedics arrived. An officer mentioned liquid was coming out of Prude's mouth.

One paramedic began performing CPR on Prude. Another stood over his shoulder and spoke to the officers.

"So, PCP can cause what we call 'excited delirium,'" she said. "I guarantee you that's how he coded. It's not your guys' fault. I mean, you gotta keep yourselves safe."

An autopsy later listed Prude's cause of death as a homicide: asphyxiation during physical restraint, with excited delirium and PCP as contributing factors.

Precedent

Several federal appellate courts have held that police generally have no obligation to use less force against people who are in a state of excited delirium.

Governments can lessen the risk of deaths, and their legal exposure, by training police to treat excited delirium as a medical emergency, but when police don't follow the policy, they don't necessarily lose their qualified immunity or expose the government to liability.

West Jordan, Utah, Police Chief Ken Wallentine writes about legal issues for Lexipol, a public safety policy and training company, and has often served as an expert witness in use-of-force cases. He said the appellate court cases do send a clear message to officers and government officials: Training is critical.

Deaths can often be prevented by police who know what the signs are, and know to treat it as a life-or-death medical emergency rather than a crime in progress. The goal, Wallentine said, is to calmly contain and cool down the subject until paramedics can safely treat them.

"I'd like to say law enforcement officers are well-aware of excited delirium," Wallentine said. "But that's not true."

The Sixth Circuit in 2017 upheld qualified immunity for officers in a wrongful death case filed by the widow of Gary Roell, a man with schizoaffective disorder who allegedly rushed officers while brandishing a hose and a garden basket. Roell died after being restrained, and an autopsy determined his death to be natural, caused by excited delirium due to his mental illness.

The appellate court held that the deputies did not use unreasonable force that violated Roell's constitutional rights, and that Hamilton County, Ohio, was not liable because it had provided excited-delirium training to the deputies — even though the deputies might not have followed the county's policy of staging medical personnel nearby and trying to verbally de-escalate the situation before using force.

Circuit Judge Karen Moore, however, dissented from the majority.

She pointed to a 2004 Sixth Circuit decision in Champion v. Outlook Nashville Inc., which held that law enforcement officers must de-escalate the situation and use minimal force in cases where a person exhibits signs of mental instability and is unarmed. It was unclear under Ohio law whether Roell, holding the hose and basket, was armed, Judge Moore said.

She contended that a jury should have resolved the question of whether police complied with their obligation under Champion to "adjust the level of force downward."

The Eighth Circuit followed with a 2019 decision in Hanson v. Best, in which the court found case law didn't support the contention that officers used unreasonable force by keeping a Minnesota man, Andrew Layton, restrained and in a prone position for a prolonged period of time. Layton later died after suffering a heart attack in the booking area of the jail.

The appellate court found that the officers' decision to summon paramedics to check on Layton before transporting him showed they did not disregard Layton's medical needs before his death.

And in Callwood v. Jones, an Eleventh Circuit panel found Alabama law enforcement officers were entitled to qualified immunity after tasing Khari Illidge, a Black man in an apparent episode of excited delirium, more than a dozen times and then hogtying him. Illidge died following the encounter.

The U.S. Supreme Court declined to take up the case in 2018.

'We Don't Have the Answer'

Zehm's killing still casts a long shadow over the Eastern Washington city of Spokane. His name still comes up regularly in conversation, local media and city politics — especially when local officers use force.

In some ways, the Spokane Police Department was 14 years ago where many police departments are now, puzzling out their techniques and legal obligations in mental-health emergencies versus criminal arrests.

The city settled with Zehm's family for about $1.7 million, and a veteran officer who beat Zehm with a baton and falsely claimed that Zehm had first attacked him with a soda bottle was convicted of using excessive force and lying to federal authorities. He served a four-year sentence in prison.

The city's police department has been transformed by Zehm's death. It submitted to an audit by federal authorities and implemented their 42 recommended reforms, established independent civilian oversight and became an early adopter of bodycams. Use-of-force incidents have dropped. Today, officers are trained in dealing with people in mental-health crises, with some who patrol full time with psychiatrists in their cars.

In a 2015 incident that won the department some local praise, Spokane officers were captured on a cellphone camera responding to reports of a nude man screaming on a residential street. They arrived without sirens and calmly surrounded and contained the man until an ambulance arrived to take him away safely. Residents watching from their doorsteps applauded.

The city's officers are trained to treat excited delirium as a medical emergency rather than a crime, said the Spokane Police Department's public information officer, Sgt. Terry Preuninger.

Breean Beggs, a civil rights lawyer who represented Zehm's family in a lawsuit against the city and is now Spokane City Council president, said the department has improved and is exploring more reforms.

Since Zehm's death, Preuninger said he has thought often about excited delirium. Officers encounter delirious people with some frequency because of drug use among homeless people in the city's downtown. Dispatchers have been trained to recognize possible excited delirium cases and summon both police and medical aid to the scene at the same time.

But he said medical experts have told him that despite their best efforts, police officers often have limited control over whether someone will survive an episode of excited delirium.

He said the footage of Prude's killing in Rochester illustrated the peril of excited delirium events. Officers can't just walk away from someone in a delirious rage, and sometimes they can't avoid using force, leaving even well-trained officers to walk a fine line that medical science has struggled to define, he said.

"We're not scientists. We're not doctors," he said. "We see these things with our own eyes, but we don't have the answer."

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