Sealed with a hiss: The letters of the “acid-bath murderer”

Scholars will be able to access childhood writings, schoolwork and the prison correspondence of the notorious serial killer, who infamously dissolved his unfortunate victims in sulphuric acid before pouring away their remains.

The collection is being housed in the University's Institute of Criminology, and includes the last letter Haigh penned to his parents, hours before he was executed in August 1949. Academics hope that the documents will provide fresh insight into his mental state and inform ongoing research into the causes of crime, and how to assess potential reoffenders.

Haigh, who was also dubbed the “acid bath vampire” by the media of the day, earned himself a place among the most notorious killers of all time for the grisly manner in which he disposed of his six victims, whom he killed between 1944 and 1949.

All the murders were carried out for the sake of financial gain, but Haigh was also mistakenly convinced that the police had to have a body to be able to bring a charge of murder against him. He therefore believed that the dissolution of a corpse would enable him to commit “the perfect murder”.

Following his release from prison in 1944, where he had been serving time for theft, Haigh killed a former friend, William McSwann, and then his wealthy parents, Don and Amy. He dumped their bodies in 40-gallon drums, immersed them in sulphuric acid until they became sludge, then poured the remains down a manhole. He then stole their pension cheques, sold their properties and moved into an upmarket hotel in Kensington.

By 1947 he had gambled away much of the money and, to replenish his bank balance, lured further victims to his workshop in Crawley. First Dr Archibald Henderson and his wife Rose were shot and dissolved, and in 1949 Haigh murdered a wealthy widow, Olive Durand-Deacon.

Police, however, became suspicious while questioning Haigh over the final murder and further investigation led them to the workshop. On the premises they found deep pools of sludge containing some of the unfortunate woman's remains – human body fat, gallstones, part of her left foot, fragments of bone and dentures. Forensic tests were carried out and Haigh was arrested, tried and imprisoned. He was eventually hanged on August 10th, 1949.

Experts are still divided as to what, beyond monetary gain, lay behind Haigh's actions. Biographers have argued that he was profoundly affected by a strict religious upbringing – both parents were fundamentalist Christians and believed they had been specially chosen by God to fulfil some “higher purpose” on earth.

Researchers at Cambridge, however, believe that further analysis of the letters could reveal that the notorious killer had a genetic predisposition to psychopathy that affected him far more profoundly than anything in his early life. The collection features correspondence from Lewes, Brixton and Wandsworth Prisons, running right up to the eve of his death on August 9th, 1949. Many were written to his parents, but there are also letters to girlfriends and various acquaintances.

Professor Friedrich Loesel, Director of the Institute of Criminology at Cambridge and an expert in forensic psychology, said: “Obviously the documents are of immense interest to us because we are involved in analysing the causes and background of serious crimes and for the first time we have the opportunity to analyse the Haigh archive from a scientific perspective.

“The really interesting thing that emerges from the letters he wrote to his parents is that he rarely addresses the question of his actual crimes. Nor does he write about his hanging. He also exhibits delusions of grandeur – he is proud to read about himself in the papers, for instance. These are typical indicators of psychopathy.

“There is also very little evidence he understood the emotional impact of what he had done; it is as if he hears the tone but does not understand the music. Obviously the intense and bigoted upbringing by his parents was important, but it may not explain the whole story. I believe there could also be a mental predisposition at stake here.”

The only acknowledgement in the letters of his pending death comes in the very last note, in which Haigh accepts this will be the last time he writes to his parents. Unlike every other letter home, in which he signs himself “Sonnie”, in this last document he also signs off as “John George”.

The collection was given to Institute by Vivian Robinson, an alumnus of Sidney Sussex College whose father had helped the Haigh parents to cope with their son's criminality. Mr Robinson was bequeathed the documents on the understanding that they should never be sold or used to make money, which led to his decision to donate them for research instead.

Increasingly, researchers believe that psychopathy is the consequence of a neurological defect in the brain that means the person does not understand the emotional or moral impact of what he or she has done. The collection provides researchers with a chance to test this theory with regard to John Haigh, by looking both at his letters and early writings from his youth, which include a school divinity essay, dated 1926 and a piece from the following year entitled “A Christmas Meditation”.

“We are very well-placed to take a truly inter-disciplinary approach to using these letters to achieve a better understanding of the role of cognitive processes and psychopathic personality disorder in crime,” Dr Loesel added. “The range of researchers available to us means that we can fully analyse these documents from different perspectives to further assess the complex causes of criminal behaviour.”