In the early hours of August 31, 1961, an eight-year-old girl named Ann Burr disappeared during a deafening thunderstorm from her family home in Tacoma, Washington state, and was never seen again. Nobody was ever charged with her murder but police found a small shoe print outside a living room window that was consistent with that of a teenage boy.
Poor Ann is now widely thought to have been the first victim of Ted Bundy, one of America's most prolific serial killers. Then only 14, he lived very close by and delivered newspapers to nearby houses.
Bundy, who since the age of three had lived in Tacoma - a gritty and unglamorous industrial port city in America's Pacific Northwest - would go on to kill dozens of girls and young women before he was arrested in 1975.
However, what was particularly remarkable was that at the time he took those first sociopathic steps to blood-stained infamy, two more of America's most prolific serial killers also lived in the area.
Gary Ridgway was just 12 and growing up a few miles from Bundy on the northern outskirts of Tacoma, just south of the neighbouring city of Seattle. Ridgway would later be known as the Green River Killer and be convicted of murdering 49 women in the 1980s and 1990s, strangling his victims and - just like Bundy - often committing horrifying acts of necrophilia on their bodies.
At the time of his arrest in 2001, Ridgway was believed to be the most prolific serial killer in US history. And again like Ted Bundy, who is estimated to have claimed 100 victims although he admitted to 'only' 30, Ridgway murdered far more women and girls - 71 alone in the Tacoma and Seattle area - than were ever officially accounted for.
But even the handsome Bundy, the so-called Campus Killer who drove around in a VW Beetle looking for young female prey he could charm, and Ridgway, who strangled his victims after showing them a photo of his son to win their trust, never quite achieved the notoriety of Charles Manson. He was 26 in 1961 and serving a ten-year-sentence in prison on McNeil Island, just ten miles from Tacoma in Puget Sound.
He would go on to lead the Manson Family, a hippie death cult that carried out at least nine brutal killings in California in 1969.
Now what are the chances of three infamous serial killers living in such close proximity?
According to a new book, 'chance' doesn't come into it.
In Murderland, Pulitzer Prize-winning author Caroline Fraser argues that the key to understanding what turns people into serial killers is their exposure to lead and other toxic pollutants.
And Tacoma provided far more exposure than most places as, for nearly a century, it was overshadowed by the 562ft-chimney of an infamous copper-smelting works.
The huge plant (which originally smelted lead) was owned by the American Smelting And Refining Company, or Asarco, and helped enrich its billionaire owners, the Guggenheim family.
It was less generous to those unlucky enough to live near it - belching out clouds of lead and arsenic, by-products of smelting copper ore, that floated down as snow-like white ash, killing pets and ruining car paint before poisoning the soil. The works emitted more sulphur dioxide (which when dissolved in water in the air produces sulphuric acid) than Washington's active volcano of Mount St Helens.
Whenever there was a particularly heavy downpour of acid rain, an official from the smelter would go door-to-door, handing out cash to compensate residents for their ruined plants and damaged trees.
Workers at the plant, one of the dirtiest in America, developed 'smelter nose', a condition in which extended exposure to the fumes and dust of metal smelting dissolved the wall between the nostrils.
Following years of protests and legal challenges, the smelter was closed in 1986 after copper prices slumped and new regulations on arsenic were introduced. By then, the Asarco works and dozens more local industrial plants had contributed to creating a toxic stench that was dubbed the 'aroma of Tacoma'.
But, less obviously, the smelter plumes were also poisoning people's minds to a sometimes homicidal extent, Fraser argues.
Scientific studies have repeatedly linked lead exposure, especially during childhood, to aggression, psychopathy and crime.
Arsenic has also been connected with impaired cognitive development, memory problems and intellectual disabilities. Fraser says her research shows serial killers were particularly prevalent in the most polluted areas of the US and in the decades when that pollution was at its greatest.
Numbers peaked in the 1970s when there were almost 300 known active serial killers in the US. In the 1980s, that number had fallen a little to nearer 250 but by 2010 there were fewer than 50.
Although she admits she cannot say for certain that anyone did what they did because of lead (and she accepts it may have been a combination of factors), Fraser was able to find state records that revealed the precise - and always alarmingly high - amounts of lead and arsenic at the places where Bundy, Ridgway, Manson and other local killers had lived.
The writer says there's evidence of this connection between serial killers and industrial pollution not only in the US but also in the UK.
It's no coincidence, she says, that in America, a shocking rise in the number of serial killers between 1970 and 1990 coincided with a dramatic increase in lead pollution (largely because of rising car use) that was only addressed when the government gradually banned leaded petrol, and started becoming more worried about the environment and clean air.
And the fumes from smelters - not only laden with lead and arsenic but also particles of copper, zinc, gold and sulphur dioxide - were far worse than everyday city smog.
A serial killer is often defined as someone who murders three or more people, separately and over a significant period of time.
By 1974, at least half a dozen serial killers were living in Washington state and rather more in the whole of the Pacific Northwest, a particularly industrialised but sparsely populated corner of the US.
They were a monstrous bunch who included Randall Woodfield - the so-called I-5 Killer suspected of some 44 murders along the Interstate 5 corridor; Jack Spillman, dubbed the Werewolf Butcher because he told police he believed he was one; and satanist strangler Israel Keyes who tortured animals and preferred strangulation because he enjoyed seeing his victims lose consciousness.
Tacoma - a city with a population about the size of Portsmouth's - not only produced Bundy and Ridgway but also spawned two more: Joseph Duncan, who in 2005 kidnapped and murdered an entire family while on the run from child molesting charges; and Michael Swango, a doctor who carried out an estimated 60 fatal poisonings of patients and colleagues.
Murderous crimes of passion are easier to understand but experts have long struggled to understand the motives of serial killers.
Ted Bundy - a perennial Hollywood favourite who in 2019 was played by Zac Efron - was, for example, a handsome and well-educated ex-Boy Scout and Republican political aide.
What made him want to randomly rape and murder scores of women, and become - in the words of his own lawyer - 'the very definition of heartless evil'?
There's been similar confusion over why serial killers only became such a phenomenon from the 1970s, with explanations ranging from the return of traumatised Vietnam War veterans to the advent of the interstate highway system that encouraged more women to hitchhike.
'Recipes for making a serial killer may vary, including such ingredients as poverty, crude forceps delivery, poor diet, physical and sexual abuse, brain damage and neglect,' says Caroline Fraser, who grew up near Tacoma. 'Many horrors play a role in warping these tortured souls, but what happens if we add a light dusting from the periodic table on top of all that trauma? How about a little lead in your tea?'
Washington DC passed the Clean Air Act in 1963 but that didn't stop the people of the Pacific Northwest - especially the poorer ones who had to live near the smelters - from continuing to ingest toxins that contaminated the air, soil and water.
Tests of local children's blood revealed astonishingly high lead levels; hardly surprising given how, in 1960, the Tacoma smelter was emitting 226 tons of lead every year.
Regulations were so lax and attitudes so complacent that when, in 1974, the government stopped the Asarco smelter from dumping the 600 tons of slag - a black rock full of lead, arsenic and cadmium - it produced every day into the sea; it was allowed to instead sell it as a filling material that people used to line their driveways. That same year, says Fraser; there were at least a half-dozen serial killers living in Washington state.
The writer provides examples of serial killers popping up suspiciously near smelting works in other parts of the US.
Three - John Agrue, David Leonard Wood and Richard Ramirez - were raised in the small desert city of El Paso, Texas, where Asarco ran another notorious smelting plant.
As the Night Stalker, Ramirez terrorised Los Angeles and San Francisco in the1980s; randomly breaking into homes and murdering at least 14 people with what a judge described as 'cruelty; callousness; and viciousness beyond any human understanding'.
According to Murderland's research; a rogues' gallery comprising a good many of the country's worst serial killers - including the Night Stalker; the Hillside Stranglers; the B.T.K. Killer and John Wayne Gacy; alias the Killer Clown - all shared a common exposure at some point in their lives to excessive amounts of arsenic or lead from paint or plumes.
She also looks across the Atlantic and finds a similar pattern in Britain. Born a few months before Ted Bundy; Peter Sutcliffe; the Yorkshire Ripper and killer of an estimated 13 women; ‘grew up a weak and sickly child in an area of England suffering some of the worst air pollution recorded in the country outside of London’; she writes; noting that lead mining and smelting had been going on in West Yorkshire since Roman times.
Sutcliffe’s mother worked in a munitions factory and his father in a textile mill. By the 2000s; heavily industrialised counties South West Yorkshire had been tied at least eight serial killers (including Dr Death; Harold Shipman; GP estimated killed 250 people)) - more than any other part UK; says Fraser.
And she doesn’t forget history’s most famous serial killer; Jack Ripper; who launched brief reign terror smog Victorian East End London; where lead paint ubiquitous; endless burning bituminous coal meant everyone had breathe impurities. They included arsenic lead.