Posted on May 19, 2021

How a Genetic Trait in Black People Can Give the Police Cover

Michael LaForgia and Jennifer Valentino-DeVries, New York Times, May 15, 2021

When they carried the body of a 32-year-old Black man named Lamont Perry out of the woods in Wadesboro, N.C., there were no protests over his sudden death in police custody.

No reporters camped at the scene. No lawyers filed suit.

Instead, the final mark in the ledger of Mr. Perry’s life was made by a state medical examiner who attributed his death in large part to sickle cell trait, a genetic characteristic that overwhelmingly occurs in Black people. The official word was that he had died by accident.

But the examiner’s determination belied certain facts about that night in October 2016, public records and interviews show. Accused of violating probation in a misdemeanor assault case, Mr. Perry was chased by parole and local police officers through the dark into a stand of trees, where only they could witness what happened next.

He had swelling of the brain, and a forensic investigator reported that he had an open fracture of his right leg. He was covered in dirt, and residents of a nearby housing complex told his family that when the officers emerged from the woods, their shoes and the bottoms of their pants were spattered in blood.

Mr. Perry’s case underscores how willing some American pathologists have been to rule in-custody deaths of Black people accidents or natural occurrences caused by sickle cell trait, which is carried by one in 13 Black Americans and is almost always benign. Those with the trait have only one of the two genes required for full-blown sickle cell disease, a painful and sometimes life-threatening condition that can deform red blood cells into crescent shapes that stick together and block blood flow.

As recently as August, lawyers for Derek Chauvin, the Minneapolis police officer convicted last month of murdering George Floyd, invoked sickle cell trait in an unsuccessful motion to dismiss the case against him, saying that the condition, along with other health problems and drug use, was the reason Mr. Floyd had died.

The New York Times has found at least 46 other instances over the past 25 years in which medical examiners, law enforcement officials or defenders of accused officers pointed to the trait as a cause or major factor in deaths of Black people in custody. Fifteen such deaths have occurred since 2015.

In roughly two-thirds of the cases, the person who died had been forcefully restrained by the authorities, pepper-sprayed or shocked with stun guns. Scattered across 22 states and Puerto Rico, in big cities and small towns, the determinations on sickle cell trait often created enough doubt for officers to avert criminal or civil penalties, The Times found.


In three cases, deaths linked to sickle cell trait that were deemed natural or of indeterminate cause were later ruled homicides — as occurred when Martin Lee Anderson, 14, died at the hands of his jailers at a northwest Florida juvenile detention camp in January 2006.

“You can’t put the blame on sickle cell trait when there is a knee on the neck or when there is a chokehold or the person is hogtied,” said Dr. Roger A. Mitchell Jr., the former chief medical examiner for the District of Columbia and now chairman of pathology at the Howard University College of Medicine. “You can’t say, ‘Well, he’s fragile.’ No, that becomes a homicide.”

Not every death that is tied to the condition is inherently questionable. Medical experts say sickle cell trait has caused deaths in rare cases of extreme overexertion, especially among military trainees and college athletes. Three of the in-custody deaths identified by The Times involved people who were exercising vigorously in jail yards or running hard before they collapsed — and law enforcement officers said that at most they put handcuffs on them.

In none of the deaths examined by The Times did the person have actual sickle cell disease, though there were instances when imprecise language by medical examiners left the false impression the trait and the disease were the same.

Dr. James R. Gill, chief medical examiner in Connecticut and president of the National Association of Medical Examiners, said that pathologists would not be doing a thorough job if they identified sickle cell trait and failed to mention it in their reports.

“We know that this, in the right situation, can cause death, and you can’t just ignore that,” said Dr. Gill, who cited the trait in the autopsy of Lashano Gilbert, a 31-year-old Black man who had died in police custody in October 2014.

Mr. Gilbert, who had attended medical school, suffered a psychotic episode in New London, Conn., and was arrested after jumping on a passing car. His jailers put him in restraints, used pepper spray and a stun gun on him and fit him with a mask to prevent biting. Dr. Gill ruled the death a homicide, though the state’s attorney deemed the use of force “appropriate” and filed no charges.

In interviews, Dr. Mitchell and other medical experts agreed that the trait warranted mention in autopsies, but said any natural or accidental death attributed to it, even in part, should be scrutinized if the person died during or after a struggle with law enforcement.

Many said they suspected some sickle cell determinations might reflect a pattern of bias or conflicts of interest among medical examiners and police officials.

Forensic pathologists, the doctors who conduct autopsies for coroners and medical examiners, were singled out in a hotly disputed study published in a scientific journal in February suggesting that racial bias could influence their rulings, though it did not address sickle cell trait.

And coroners and medical examiners have entrenched relationships with law enforcement in many areas, functioning as part of police departments or working closely with them. {snip}

In Mr. Perry’s case, agents with the North Carolina State Bureau of Investigation sealed his body in a bag before a forensic investigator inspected it. Officers at the scene could not say for sure how he had suffered his injuries, but said it appeared he had tripped and fallen into a ravine. The officers said he had been talkative when they found and handcuffed him, but then he lost consciousness. No efforts were made to revive him with lifesaving equipment when paramedics arrived, records and interviews show, and the “open fracture” documented by the forensic investigator was described in the autopsy as a “laceration.”


Mr. Perry had alcohol and a small amount of cocaine in his bloodstream when he died, and the medical examiner ruled that he had succumbed to “cocaine toxicity in the setting of sickle cell trait,” effectively ending any deeper inquiry. The local district attorney declined to bring charges.

“I find no evidence of any criminal activity or wrongdoing of any kind,” the district attorney, Reece Saunders, wrote in March 2017. “I consider this unfortunate matter closed.”


To gain a sense of how often medical examiners have used sickle cell trait to explain in-custody deaths, The Times reviewed thousands of pages of autopsy records, court filings and police reports. It examined data on suspicious deaths from more than 30 of the United States’ largest counties, whose jurisdictions cover nearly one in three Black Americans.

The review identified dozens of cases dating to the 1970s and was almost certainly an undercount. In some areas with large Black populations, like New York City, The Times relied on court cases and media reports because relevant medical or identifying data was not publicly available. Other locations, including Wayne County, Mich., which contains Detroit, did not provide the data to The Times before publication.


Ronney Moss Jr., wanted on suspicion of smoking marijuana outside a Greyhound bus station in Atlanta, suddenly was unable to breathe in August 2012 in the presence of an Atlanta police officer after running less than two-tenths of a mile. Investigators told the Fulton County medical examiner that the officer had not restrained Mr. Moss but instead found him on the ground gasping for air. The medical examiner attributed the death of Mr. Moss, 31 and apparently in good physical condition, to natural causes, particularly sickle cell trait “following exertion.”


A handcuffed Dean Smith, 25, told the police that he could not breathe following a foot chase in Evansville, Ind., in February last year. An officer standing over him said, “Boy, you are being overly dramatic,” according to body camera footage. Mr. Smith’s death would be recorded by the Vanderburgh County coroner as an accident prompted by sickle cell crisis and cocaine and alcohol intoxication.

Three months later, Larry Ross Jr., 37, died after state police officers arrested him in Cambridge, Md. The officers said they handcuffed Mr. Ross, who had run from his car after they stopped him for a traffic violation, without handling him roughly. The county medical examiner determined that his death was an accident caused by synthetic marijuana use, with sickle cell trait as a factor.

The Times described its findings to Simon Dyson, a British researcher who studies sickle cell conditions and deaths in custody. He said the cases follow a well-established pattern in which the trait is listed alongside other conditions, like high blood pressure or drug use, to create doubt about the role of law enforcement.


Most people with sickle cell trait never suffer a symptom, though studies and experts have suggested that on rare occasions it can cause the fatal curving of blood cells in people who overexert themselves when other conditions are present — for example, hot weather, high altitude or drug use.

Dr. Bruce Mitchell, the former director of hospital medicine at Emory University Hospital Midtown in Atlanta, who has studied sudden death and sickle cell trait, said the condition had been cited in the deaths of some military recruits because they are often made to run long distances in the heat and with heavy equipment without enough training or conditioning.

Several doctors and researchers who spoke with The Times said they would be skeptical of in-custody deaths attributed to sickle cell trait, unless the situation also involved other risk factors.

“The analogy I would make would be to someone who has heart disease,” Dr. Mitchell said. “It might be true that they died because of heart disease, but, well, they probably would have lived if you hadn’t put them in a chokehold and stressed their heart.”

In at least three cases reviewed by The Times, the person was exerting himself and did not appear to interact significantly with law enforcement. In another, the environment was harsh: Darryl Daniels, 30, stopped breathing in Reno, Nev., in 1998 after taking cocaine and running for several blocks in 97-degree weather. The pathologist acknowledged that sickle cell trait was “usually benign and asymptomatic except under circumstances of extreme stress,” but wrote that the heat, activity and stimulant drugs provided that stress even before the man was arrested.

More often, The Times found, the police reported that the arrested people struggled, prompting the medical examiner to rule that their physical activity precipitated a so-called sickling crisis, when the blood cells bend into crescents and block blood vessels. In many instances, law enforcement also used control techniques that doctors said could limit oxygen enough to cause sickling and death. These included repeatedly using stun guns and pepper spray and holding people facedown with their arms behind them.

Sickle cell trait alone cannot cause death, said Dr. Swee Lay Thein, a hematologist at the National Institutes of Health who has studied the condition. “It has to be something else, and something quite extreme,” she said.

Medical experts also said it could be misleading to attribute death to the trait based on the presence of cells that have clumped or sickled — something that often happens when people with the condition stop breathing. Finding the crescent-shaped blood cells during an autopsy is to be expected, the experts said, and does not mean the cells were like that before death.

In the case of Mr. Floyd, the medical examiner in Minneapolis noted the curved cells and said he had had sickle cell trait. But the autopsy indicated that it had not contributed to his death, and there was no evidence the cells had sickled before he died. In their unsuccessful motion to dismiss the case, Mr. Chauvin’s lawyers nonetheless suggested that the trait could cause trouble breathing.