What killed Daniel Prude? The 41-year-old died in March 2020 after cops pinned him down during a drug-induced mental health crisis. For three minutes, Rochester, New York, police officers pressed Prude’s head and torso into the street, continuing their hold for nearly a minute after he began vomiting. It was one of the highest-profile deaths in police custody in a year that saw a historic nationwide movement against police brutality.
According to a state investigation, an autopsy, and the cops who held him to the ground, Prude was killed by something called “excited delirium.” The condition is said to turn people into erratic aggressors and can supposedly lead to cardiac arrest.
Authorities cited excited delirium in other notorious Black Lives Matter-era deaths in police custody, including those of George Floyd, Elijah McClain, and Angelo Quinto. The purported diagnosis had become so popular among first responders that, in Rochester, paramedics speculated even before they saw him that Prude was likely experiencing the condition, according to the state investigation.
Yet in the last four years, a vast swath of the U.S. medical establishment has rejected excited delirium as a diagnosis. Six leading national medical associations have fully disavowed it, while another two have distanced themselves from it. Floyd’s home state of Minnesota, McClain’s Colorado, and Quinto’s California have barred public officials from citing the syndrome.
A “Debunked” Theory
Medical experts say excited delirium is a theory, not a recognized disease with a specific physiological cause. And they have argued it can obscure the actual causes of deaths, especially when police are involved.
Now, a training document obtained through a public records request by New York Focus and The Intercept sheds new light on how the disavowed diagnosis infiltrated the Rochester Police Department before Prude’s death.
Advocates and researchers blame the initial popularization of the excited delirium diagnosis on a corporate-backed campaign to absolve cops of responsibility for deaths in their custody. In Rochester, the training document, created in 2016 and last edited in late 2020, lifts directly from materials disseminated by an organization linked to Taser, producer of the eponymous stun gun. The document warns officers that the syndrome’s sufferers experience a “diminished sense of pain” that could render police batons ineffective. And it claims that “saying ‘I can’t breathe’” is a sign of excited delirium.
“It displaces any sort of blame from the perpetrator of violence — in this case, the police — to the person who’s on the receiving end.”
“It displaces any sort of blame from the perpetrator of violence — in this case, the police — to the person who’s on the receiving end, but under the guise of this diagnosis,” said Altaf Saadi, a neurologist at Massachusetts General Hospital, of the training document. Saadi, who has done research on how excited delirium rose to prominence, reviewed the training materials for New York Focus and The Intercept.
The document comes to light as New York grapples with its role in promoting excited delirium as a cause of death. After Prude died, state Attorney General Letitia James encouraged first responders to embrace the disputed concept.
“Personnel must be trained to recognize the symptoms of excited delirium syndrome and to respond to it as a serious medical emergency,” she recommended in a 2021 report.
Photo: Michael M. Santiago/Getty Images
It’s unclear how many police departments in the state have trained officers on the theory — though the largest one has. Last year, New York Focus uncovered New York City Police Department training materials that provide guidance on excited delirium similar to what is in the Rochester document. (The NYPD did not respond to a request for comment.)
Internally, the attorney general’s office has softened its stance.
In a statement, the office said, “Causes of death are solely determined by medical examiners, not OSI” — James’s Office of Special Investigation — “however we have not recognized ‘excited delirium’ or similar terms as a cause of death for several years because we are acutely aware of the scientific discourse and concerns regarding the term.” Her office did not comment on her use of the term in the Prude investigation nor her guidance that officers should be trained on the theory.
“It’s pseudoscience that all too often provides cover for fatal police tactics.”
With James avoiding a full-throated rejection of excited delirium, state lawmakers are taking up the fight. Citing New York Focus’s report on the NYPD, Assemblymember Jessica González-Rojas introduced legislation in March to ban government agencies from referencing excited delirium.
“The term has been debunked by the major medical associations,” said González-Rojas. “It’s something that has to be done.”
She said, “It’s pseudoscience that all too often provides cover for fatal police tactics.”
“No Such Medical Disease”
“Excited delirium syndrome” was scientifically suspect from the start. In the 1980s, doctors studying cocaine use in Miami coined the term to describe how, in their observations, the drug could make men “psychotic” and potentially cause women to die during sex. The deceased women the doctors initially studied were later found to be victims of a serial killer. Other subjects had been restrained by police in positions that can obstruct breathing.
Still, the notion gained traction, and in 2005, a forensic pathologist and psychiatric nurse published a book on the syndrome. In the opening pages, it reads, “This book is dedicated to all law enforcement and medical personnel who have been wrongfully accused of misconduct in deaths due to excited delirium syndrome.” The publication caught the eye of Taser.
Amid increased scrutiny over its stun guns’ role in deaths involving police, Taser became one of the excited delirium theory’s biggest boosters. The company distributed the book and other literature on the syndrome. Taser-backed research made its way into first responder training materials, which recommended tactics to subdue excited delirium sufferers — including by using Taser stun guns.
The company hired experts who testified in police killing trials that the syndrome, and not stun guns or other uses of force, caused the victims’ deaths. Some of the same experts inundated medical journals with studies making the same arguments. Taser, now known as Axon, did not respond to a request for comment.
Taser concentrated much of its advocacy on medical examiners, whose autopsies play a key role in legal proceedings for police killings. Between 2000 and 2017, medical examiners listed excited delirium as a factor in at least 276 deaths that followed Taser use, a Reuters investigation found. (Little to no public data exists on how many overall deaths are attributed to excited delirium.)
Joye Carter Rush, a forensic pathologist and former longtime medical examiner, remembers receiving Taser materials on excited delirium, including the 2005 book. The dedication jumped out at her.
Taser’s medical examiner advocacy was peculiar, Carter Rush said, because there’s no special way for medical examiners to diagnose the syndrome. Rather, as a “syndrome,” it’s a list of simultaneous symptoms.
“There is no such medical disease as excited delirium,” Carter Rush said.
Excited delirium is sometimes linked with drug use, but the behaviors police have come to associate with it can result from a wide variety of underlying causes, medical experts said.
“Maybe they have dementia, maybe they have autism with behavioral issues,” said Saadi, the neurologist. “If they’re having fever and muscle rigidity” — among excited delirium’s listed symptoms — “it could be encephalitis. There’s literally so many different diagnoses.”
“‘Superhuman strength’ and ‘unlimited endurance’ we know are racist tropes.”
That murkiness is what prompted some of the top medical associations, including the American Medical Association and the American Psychiatric Association, to fully disavow the diagnosis.
Excited delirium’s reputation for endowing sufferers with super strength and imperviousness to pain can fuel more aggressive police responses, Saadi said.
“‘Superhuman strength’ and ‘unlimited endurance’ we know are racist tropes that have been typically used against Black men,” said Saadi. “It sends the message that it is okay to justify having this super aggressive escalation when that is often not the case.”
Zombie Pics
The Rochester materials obtained by New York Focus and The Intercept highlight critics’ concerns about excited delirium.
Look out for subjects who look like they “just snapped,” the training warns. Excited delirium may render “pain compliance techniques” like batons ineffective.
To reinforce the unearthly qualities of people experiencing the syndrome, the training presentation includes melodramatic photos and illustrations: deranged people screaming; a naked, bloody zombie eating a corpse; the Incredible Hulk. In one image, two cops pin a naked, wide-eyed Black man to the ground.
Obtained by New York Focus and The Intercept
The training file’s metadata indicates that it was created in 2016 and last edited in late 2020, meaning it was likely offered to officers before Prude’s death.
The metadata also shows that the file was created by the Monroe County Office of Mental Health’s former chief of clinical and forensic services, Kimberly Butler, who also headed the county team that accompanies police on mental health crisis calls.
Butler, who did not respond to interview requests, resigned in 2020 after it was revealed that she sent privileged information about Prude’s mental health care to Rochester police officials after his run-in with the cops. She was one of at least 16 public officials, including the Rochester police chief, to resign, retire, or get fired in connection with their handling of the Prude case.
Both the Rochester Police Department and the Monroe County Office of Mental Health said that they don’t currently offer the excited delirium training. (The police department sent the file to New York Focus and The Intercept in response to a request for “currently used” training materials related to excited delirium.)
“It was co-sponsored by the county Office of Mental Health, and we do have officers who attend Office of Mental Health trainings, but I have no idea if they still use it or not,” Greg Bello of the Rochester Police Department said.
A spokesperson for the county Office of Mental Health said that the training document is from a prior administration — the current director took over in February 2021 — and the office can’t be sure when the last time it was used. Neither the police nor the mental health office responded to follow-up questions about their stances on excited delirium.
Taser Tag
Most of the Rochester training presentation’s first half — including the line that lists “saying ‘I can’t breathe’” as a sign of excited delirium — appears to lift directly from an informational poster published by a group called the Institute for the Prevention of In-Custody Deaths.
The group was co-founded by a former Taser-paid expert named John Peters and a Taser attorney around the same time that the company’s excited delirium campaign was in full swing. The informational poster, written by Peters, touts that Taser’s stun guns “have been shown to be the most effective to quickly capturing” excited delirium patients.
In an interview with New York Focus and The Intercept, Peters, a longtime police administrator, said he now agrees with many of the medical establishment’s concerns about the diagnosis. The IPICD has recommended against using the term for nearly 15 years, he said. The organization now teaches officers to address what it calls “agitated chaotic events,” while leaving medical diagnoses to medical professionals.
The IPICD’s website, however, still boosts the theory. An advertisement for a current institute police training course, for example, decries pushback against excited delirium as a result of “post-George Floyd societal culture.”
The IPICD also still publishes the informational poster that appears to have inspired the Rochester training presentation. The poster is nearly two decades old and cites the 1980s cocaine research. Peters said that he planned on replacing the poster after the IPICD’s annual conference in November, but it remains on the group’s website.
Photo: Joshua Rashaad McFadden/Getty Images
Attorney General Report
Taser’s connections to the Prude case extend beyond the IPICD-inspired Rochester police training.
In 2021, Gary Vilke, a San Diego-based emergency medicine doctor, became the New York attorney general’s chief medical expert in the Prude case. As a frequent paid expert witness in police killing trials, including for Taser, Vilke has earned notoriety as one of the most influential members of a cadre of hired guns whose testimonies help absolve officers.
In a deposition last year, Vilke reportedly said he consults on more than a dozen cases a year and can earn as much as $50,000 per case. He said in a 2021 deposition that for nearly two decades he never blamed a cop for a death, according to the New York Times. (He told the Times that he did not recall the statement and disagreed with it.)
He was also one of excited delirium’s most visible proponents, co-authoring a seminal white paper on the theory at an early IPICD conference.
In Prude’s case, Vilke, who did not respond to a request for comment, was confident that police weren’t at fault. He told the grand jury, convened to examine whether the cops should be charged with negligent homicide, that Prude died of excited delirium and not at the hands of the officers.
“I wouldn’t do anything differently,” he told a grand juror who asked if officers could have treated Prude better. The body voted 15–5 against charging the officers.
The office of James, the attorney general, retained Vilke to advise on its investigation into Prude’s death, making him its sole cited outside medical expert.
The Monroe County medical examiner, who still works in that role and whose office declined to comment, ruled that Prude had died from “complications” from asphyxiation, excited delirium, and intoxication from PCP, the dissociative drug he was using. While a police practices expert hired by the attorney general said that pinning Prude on his stomach for three minutes was “unreasonable” and likely caused his death, Vilke steered investigators back toward excited delirium.
“Vilke noted that Mr. Prude displayed many symptoms consistent with Excited Delirium,” the attorney general’s office reported. The syndrome, brought on by his PCP use, “caused Mr. Prude to suffer cardiac arrest.”
In its final report, issued in February 2021, the attorney general’s office dedicated nine pages to the topic of excited delirium. It acknowledged the controversy around the syndrome and its racial implications but declared that excited delirium is real and can cause sudden death.
It was in the report that James’s office made its recommendation that first responders be trained in excited delirium. The report said the Rochester police academy barely taught the syndrome. It did not account for the police training materials produced by the Office of Mental Health.
