David Tennant has opened up about taking on one of his darkest roles yet for Des, a new ITV drama about serial killer Dennis Nilsen.
The three-part series is set in the aftermath of his arrest in 1983, after police found the drains under his apartment blocked by the remains of his victims.
Out of respect for the dead, the programme doesn't show the murders, instead dedicating its time to unpacking the psychology of a killer from his time in custody.
Tennant spoke to Radio Times about how he inhabited the role, delivering a chilling performance in the lead opposite Daniel Mays as Detective Chief Inspector Peter Jay.
He explained: “There is some footage of Nilsen in an interview he did with Granada Television when he was in prison, and he was an avid home movie-maker, some of which survive, so we were able to see those.
“It was a useful starting point to see how he moved and how he sounded, as there are occasional bits of audio of him around, too. And of course the notebooks – he wrote and wrote and wrote in prison.”
Of course, a primary concern for Tennant was ensuring the show did not cross any lines with the surviving relatives of Nilsen's victims, with producers taking time to reach out to those affected by his crimes for their guidance.
Tennant added: "When you’re making a story about something that is living history, you must do it sensitively. You are talking about things that are still very raw and we were aware of that every day on set and in the edit.
"We were always discussing this, even down to what cards you put up at the end [before the credits of the third and final episode] to talk about what happened after the event."
Des also stars Jason Watkins as biographer Brian Masters, who went on to write a book about Nilsen titled Killing for Company, published in 1985.
Read the full interview with David Tennant in this week's Radio Times magazine, out Tuesday. Des premieres on ITV at 9pm on Monday 14th September. If you're looking for something to watch tonight, check out our TV Guide.