Here's How Many Victims Serial Killer Dennis Nilsen Really Had

Like many serial killers before and after him, Dennis Nilsen appeared to be a "mild-mannered civil servant" when he was arrested at his home in North London in October 1983. The arrest came after a plumber arrived to fix a clogged drain and found evidence of human remains in Nilsen's apartment. As reported by The Herald, when asked if the remains belonged to one or two people, Nilsen chillingly replied, "15 or 16, since 1978." 

Nilsen was born in Aberdeenshire, Scotland, in 1945. His parents divorced when he was young and he grew up living with his mother, two siblings, and grandparents. He formed a close bond with his grandfather and was bereft when he died. Per Biography, Nilsen said the unexpected loss and the viewing of the body in its casket are the roots of his problems. A shy and lonely child, Nilsen realized he was gay as a teenager and felt shame and guilt. Indeed, homosexuality was illegal in Scotland until 1980, so he would have been painfully aware that his attractions to other men were at the time literally crimes, per The Guardian.

Dennis Nilsen eventually joined the British Army, where he served as a cook and butcher in the Army Catering Corps. After leaving the service in 1972, he entered police training, where he was reportedly fascinated by morgue visits and autopsied bodies and went on to become a recruiter. He was questioned by the police in 1973 when a friend claimed Nilsen had taken pictures of him while he was sleeping. Nilsen apparently had to be hospitalized with a breakdown after the friend confronted him.

Nilsen murdered his first victim on December 29, 1978. He met the man at a pub, and the two returned to Nilsen's apartment and spent the night together, as reported by Biography. The next morning, desperate to keep the man from leaving his apartment, Nilsen strangled the victim and drowned him in a bucket of water. Nilsen then washed the corpse and put it in his bed, where he attempted necrophilia and slept next to the body before hiding it under his floorboards for several months. He eventually buried the remains in his backyard, thus beginning a pattern. In October of 1979, a student went to the police and reported that Nilsen had attempted to strangle him during a bondage session, but nothing came of it. 

Two months later, Dennis Nilsen killed a second man after meeting him in a pub. The second murder was nearly identical to the first, with Nilsen removing the man's body from beneath the floorboards on occasion to talk with him as if he were still alive, per Biography. Nilsen killed again in May of 1980 when he brought home a houseless 16-year-old boy. The murders of a 27-year-old sex worker and a 24-year-old orphan with learning disabilities followed. 

By 1981, Nilsen had killed 12 people, but only the above-mentioned four could be identified. Nilsen later told authorities that he went into a "killing trance" when murdering people and actually freed seven people before killing them because he was able to snap out of the trance. When he was finally arrested in 1983, Nilsen was charged with a total of 15 murders. He had moved from his apartment at 195 Melrose Avenue in North London (shown above) to a new apartment at 23 Cranley Gardens, also in North London, where he killed three more men between 1982 and February 1983. Upon his arrest in October 1983, the remains of his final three victims were found in the pipes below his clogged sink and throughout his apartment. As reported by The Herald, when asked by authorities why he had murdered all those people, Nilsen replied, "I'm hoping you will tell me that."