Dennis Nilsen killed fifteen men in the safety of his own flat in London between December 1978 and February 1983.
Nilsen would talk the men into coming to his place where he would get them drunk and strangle them. He then undressed the body and washed it, then he would cut the body into pieces, storing parts into a plastic bag and flushing other parts down the toilet.
Dennis Nilsen was born on the 23 November 1945, the son of a drunk Norweigan soldier. His mother, Betty Whyte, divorced his father eight years later and they moved into his grandparents house. Dennis was heartbroken when his grandfather died as he had been very attached to him, he later stated that this had caused his own emotional death. His mother remarried when he was nine and he effectively turned into a loner, of his first murder committed he explained that his motive was that he was lonely and emotionally hurt.
Nilsen was finally caught when on the 8 February 1983, a drains maitenance engineer was checking on a drainage system in Muswell Hill, London, that had received complaints from tenants that it was blocked. When the engineer checked it he discovered it to be blocked with human flesh, the police were notified immediately.
When a detective asked 37-year-old Nilsen (who was a tenant at the flats) about the blocked drains, Nilsen invited him into his flat. The detective noticed a foul odour, then Nilsen told him that the rest of the body was contained in bags. When Nilsen was arrested, he calmly confessed to killing 15 men. In his flat they found numerous body parts, much of it stored in bags; included in the gruesome collection was 2 severed heads and the lower part of a torso.
On the 4 November 1983, Nilsen was found guilty on 6 charges of murder (even though he had confessed to killing 15) and was sentenced to life imprisonment.