The chilling true story of Dennis Nilsen – the barbaric gay serial killer who horrified a nation with his sickening crimes

Dennis Nilsen and David Tennant side by side, wearing identical blue shirts and glasses

The story of Dennis Nilsen, one of the UK’s most prolific serial killers, is being retold in ITV’s new drama, Des.

Des, starring David Tennant as Nilsen, explores the life of the gay serial killer and necrophile known to a generation as the Muswell Hill Murderer, after the north London suburb where he committed his crimes.

The three-part series takes its name from the nickname Nilsen used to make himself seem more approachable to his victims: young men and boys, many of whom were gay and homeless.

He was jailed for life after police found human remains clogging the drains outside of his home. He’d been boiling, burning and sometimes flushing the dismembered bodies of his victims, the final steps in a chilling routine he’d developed.

While Des will no doubt make unsettling viewing, the true story behind the drama is even more horrifying.

David Tennant as Dennis Nilsen in Des. (ITV)

David Tennant as Dennis Nilsen in Des. (ITV)

Who was Dennis Nilsen?

Dennis ‘Des’ Nilsen was born in Scotland in 1945, and according to the now-defunct website Crime Library, he was especially close to his grandfather who died when he was six.

The serial killer was traumatised by seeing his grandfather’s corpse in an open casket – an experience he would later suggest led to his fascination with corpses.

As a teenager, he realised he was gay, but his sexual orientation left him confused and ashamed, so he attempted to suppress it.

In 1961, shortly after finishing school, Nilsen decided to join the army as a chef, and he gradually developed butchery skills.

During his 11-year military career, Nilsen tried to distance himself from his colleagues to further quash his attraction to men.

But, when he was finally given his own room, he said he would lie in front of a mirror so as not to see his own head. Pretending that his own body was an unconscious man, he would masturbate in front of his own reflection.

He eventually left the army, and in 1972 he retrained as a policeman, although he resigned after a few months.

In 1975 Nilsen met a man called David Gallichan, and after spending a single night in each other’s company they decided to move in together. They decorated their new north London home and bought a puppy and a cat together, but eventually the relationship began to break down. 

They broke up, and Nilsen became increasingly solitary and lonely. A year and a half later, he murdered his first victim.

The serial killer murdered at least 12 men and boys and attempted to kill seven others.

Dennis Nilsen was jailed for life in 1983 after a horrific six-year spree which saw him kill at least 12 men and boys and attempt to kill seven others, most of whom were gay or homeless.

His first victim, Stephen Holmes, was just 14 years old. According to his written confessions, Nilsen and the boy spent the night together after meeting at a pub, but in the morning Nilsen was “afraid” to wake Holmes “in case he left me”.

So, he decided that the boy would stay with him “over the New Year whether he wanted to or not”.

He strangled and drowned Holmes before bathing him and washing his hair. He engaged in necrophilic acts with Holmes’s body, then kept him under the floorboards for eight months.

While living in two separate homes in north London, Nilsen stuck to a pattern, luring his victims into his home with offers of food, alcohol and shelter, before strangling and drowning them.

He then completed similar rituals in which he bathed their bodies, dressed them, engaged in sex acts with them and lived with them for weeks or months.

Nilsen would then dismember and dispose of them by burning the bodies in a bonfire, boiling them or flushing parts down the toilet.

Dennis Nilsen was finally arrested at his house in 1983.

Nilsen’s killing spree between 1978 and 1983 only ended when police found bones and human tissue clogging the drains outside his house.

He immediately confessed, and initially claimed to have murdered at least 15 people, although he did not identify all of them.

He was convicted of the murders of six men and boys: Kenneth James Ockenden, Martyn Brandon Duffey, William David Sutherland, Malcolm Barlow, John Peter Howlett and Stephen Neil Sinclair.

There were others who survived, and Nilsen was also convicted on two counts of attempted murder.

He was sentenced to life in prison in November 1983. Nilsen provided some early notebooks to biographer Brian Masters, who used them for his 1985 book Killing for Company: The Story of a Man Addicted to Murder. 

Although Nilsen never revealed his motive for the murders, the book’s title references the common theory that he killed and kept the bodies of men and boys in order to have male company.

The serial killer died in prison in 2018, at the age of 72, from cancer.

Des begins on ITV Monday (September 14) at 9pm, and continues Tuesday and Wednesday.