David Tennant interview: The Des star reveals what it was like to play serial killer Dennis Nilsen

David Tennant in "Des" on ITV.
David Tennant does looks surprisingly like the real Dennis Nilsen (Image credit: ITV)

David Tennant is playing notorious British serial killer Dennis Nilsen in Des — the dark new drama that runs from September 14 to 16 on ITV. Amazingly, David looks incredibly like the murderer himself so he gives a chilling performance that's already causing an expectant buzz.

Dennis Nilsen's story is a macabre one. After police were called to a block of flats at 23 Cranley Gardens, in North London in February 1983, following the discovery of human remains in a drain, they were stunned when one of the residents, 37-year-old Dennis Nilsen, calmly confessed to having killed "15 or 16" people since 1978. 

Now the three-part drama Des sees David Tennant starring as job centre worker Nilsen, known to his colleagues as "Des." The show explores how the horrific crimes of one of Britain’s most prolific serial killers were investigated and how he was eventually sentenced to life in prison for six murders and two attempted murders. 

We caught up with Tennant, who tells us much more about Des and how he prepared to play such a sinister role based on a real killer…

Des on ITV: David Tennant remembers the moment Dennis Nilsen was arrested ...

DCI Peter Jay (White Lines star Daniel Mays) led the investigation. But as he battled to get justice for the victims — many of whom were vulnerable or homeless young men who Nilsen had befriended, finding the evidence to convict the killer proved tricky.

"I was about 12 when Nilsen was arrested and he was like a bogeyman," says Tennant, the former Doctor Who star. "There’s a gulf between his apparent normality and the extraordinariness of what he did. As soon as Nilsen was caught, he didn't stop talking, he confessed to everything. But many victims remain unidentified because he didn't give a lot of names. The police work was about tracking people down."

Detective Chief Inspector Peter Jay (Daniel Mays) with Nilsen (David Tennant) in ITV's Des

Daniel Mays as detective Peter Jay after having arrested killer Dennis Nilsen (David Tennant). (Image credit: ITV)

Des on ITV: How David Tennant got into the mindset of serial killer Dennis Nilsen?

Des also follows the case through the eyes of biographer Brian Masters (played by The Crown’s Jason Watkins), who interviewed Nilsen in prison for his book Killing for Company, on which the drama is partly based.

While David Tennant read the book and met Brian, he also watched numerous documentaries to get into the mindset of Nilsen, who died in prison in 2018 at age 72.

"I tried to think myself into that space," Tennant says. "But I continue to change my mind about his motivation. What happened to him that flicked that switch?"

Jason Watkins as Brian Masters in ITV drama Des

Jason Watkins as writer Brain Masters in David Tennant's drama "Des." (Image credit: ITV)

Des on ITV: Has playing Dennis Nilsen been David Tennant’s most challenging role to date?

Although Tennant has taken on the role of a killer before in C4’s Deadwater Fell and has also played The Doctor in Doctor Who, a demon in Good Omens and the antisocial DI Hardy in Broadchurch, there was something about starring as one of Britain’s most prolific serial killers that David found particularly challenging.

"Reading a script that was as dark it this was you thought nobody is ever going to dare make this," says Tennant. "Also it feels like you kind of carry a responsibility because it's a true story, because Nilsen did terrible things and because there are still people alive who are still devastated by the things he did."

David also admits he wasn’t his normal jokey, fun self on set.

"I think I’ve probably been more dour than I would normally be," he admits. "Probably less larkey I think, and just a little bit more contained."

Nicholas Cannon
TV Content Director on TV Times, What's On TV and TV & Satellite Week

I'm a huge fan of television so I really have found the perfect job, as I've been writing about TV shows, films and interviewing major television, film and sports stars for over 25 years. I'm currently TV Content Director on What's On TV, TV Times, TV and Satellite Week magazines plus Whattowatch.com. I previously worked on Woman and Woman's Own in the 1990s. Outside of work I swim every morning, support Charlton Athletic football club and get nostalgic about TV shows Cagney & Lacey, I Claudius, Dallas and Tenko. I'm totally on top of everything good coming up too.