In 1980s Miami, pathologists were left perplexed by a string of unexplained deaths.

Over a period of years, from 1980 until 1989, dozens of women were found sprawled in alleyways and junkyards but no cause of death could be found.

At first, the hallmarks were the same: they were all Black sex workers, naked from the waist down, with low levels of cocaine in their bloodstream.

Yet there was no sign of injury, no gunshot wounds, no stabbings.

A breakthrough appeared to come at last in 1988, when Dr Charles Wetli - then deputy chief medical examiner for Miami Dade County - announced that autopsies "have conclusively shown that these women were not murdered".

The answer lay in research that Dr Wetli had been conducting into a phenomenon he termed "excited delirium".

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In 1985, he had published a paper in the Journal of Forensic Sciences which described how the condition would lead to spontaneous respiratory collapse and death in cocaine users despite the concentrations found in their bloodstream being ten times lower than the amounts normally seen in fatal overdoses.

Five of the seven deaths outlined in the paper had occurred in police custody, but when Dr Wetli came to apply it to the women's deaths in 1988 he explained that "for some reason with chronic cocaine use the male of the species becomes psychotic and the female of the species dies in relation to sex".

The theory should have unravelled when a 14-year-old girl turned up dead in 1989, mirroring the circumstances of the previous victims but with the crucial distinction that she was not a prostitute, had never used drugs, and had no trace of cocaine in her system.

The investigation ultimately led detectives to the true culprit: rapist and serial killer, Charles Williams, who was suspected of murdering all 32 women by choking them to death during forced oral sex (he died in 1994, before going to trial).

The Herald: A total of 32 women were found dead in identical circumstancesA total of 32 women were found dead in identical circumstances (Image: Getty)

But instead of withering away in the years after the Miami scandal, the idea of excited delirium told hold in forensic medicine and flourished in law enforcement.

By 2006, a book on Excited Delirium Syndrome (EDS) was being distributed to every forensic pathologist in the United States despite the term remaining unrecognised by the World Health Organisation or the Diagnostic Statistical Manual (which classifies mental disorders).

Dr Wetli testified repeatedly as an expert witness in cases where suspects had died after being apprehended by taser, arguing that the real cause of death was excited delirium.

When it was observed that 70% of the men who died in this way were Black, Dr Wetli argued that perhaps Black people were just "more prone to spontaneously dropping dead due to excited delirium" and that it "might be genetic".

Critics noted that claims the condition induced erratic behaviour and bouts of "superhuman strength" might be a useful get out in cases of police brutality, as well as priming officers to use excessive force during arrests.

Notably, one of the officers involved in detaining George Floyd - whose death in May 2020 unleashed the Black Lives Matter movement - was heard to say: "Roll him on his side, I just worry about excited delirium."

The Herald: Black Lives Matters protesters in 2020, in the wake of George Floyd's deathBlack Lives Matters protesters in 2020, in the wake of George Floyd's death (Image: Getty)

Two months later, in July 2020, Dr Wetli - who had coined the term 35 years before - died from complications related to lung cancer.

His controversial hypothesis had long since gone global.

Giving evidence to the Sheku Bayoh inquiry in November last year, Police Scotland's former head of safety training, Inspector James Young, said its officers had been taught how to spot excited delirium in 2015 - the same year that the 31-year-old died after being restrained by police in Kirkcaldy.

The cause was described as "sudden death in a man intoxicated" - Mr Bayoh had consumed ecstasy and another illegal stimulant - but he had also sustained 23 separate injuries.

Why is all this relevant now?

On Thursday, an article in the BMJ revealed that the Faculty of Forensic and Legal Medicine (FFLM) - a branch of the Royal College of Physicians - is bringing forward changes to its guidance, originally scheduled for October 2025, which will remove references to "disproportionate superhuman strength" in describing excited delirium and a related term - acute behavioural disturbance (ABD) - which is more commonly used in the UK.

It comes after the Independent Office of Police Conduct (IOPC) - the watchdog for England and Wales - removed the disputed phrase from its incident forms, describing excited delirium as "outdated and potentially offensive".

Meanwhile, a July 2023 study found that mentions of ABD in mental health records in one London trust had increased year-on-year between 2006 and 2021, and that Black people were more than twice as likely to have ABD referenced in mental health assessments than white people.

The Herald: Sheku Bayoh’s mother Aminata Bayoh (left) and sister Kadi Johnson with lawyer Aamer Anwar outside Capital House in Edinburgh in May 2022Sheku Bayoh’s mother Aminata Bayoh (left) and sister Kadi Johnson with lawyer Aamer Anwar outside Capital House in Edinburgh in May 2022 (Image: PA)

Furthermore, a US analysis of 166 reported deaths in police custody between 2010 and 2020 where excited delirium was blamed found that Black people accounted for 43% of them, while a separate study found that excited delirium is most often cited as a cause of death in people who have previously been restrained.

James MacCabe, a professor of epidemiology at King’s College London, told the BMJ that the use of either ABD or excited delirium is misguided, adding that they are "used as a way of explaining the fact that people have died when they’ve been in police custody or when they’ve been restrained, and it’s a way of deflecting attention away from the restraint techniques that might have been used".

The FFLM stresses that ABD is not a standalone diagnosis but an umbrella term for a range of conditions that might include head injury, heat exhaustion, and hypoxia, or physiological complications triggered by severe anxiety.

Dr Margaret Stark, its president, insisted that its purpose in promoting the term is to raise awareness of the need "to get people to hospital and out of the police station" if they began to display ABD-type symptoms, which could become a medical emergency.

Ditching "excited delirium" is one thing, however; expunging the racist thinking it sowed for decades will be a tougher task - even if we do call it ABD.