7 Questions with… David Tennant on playing real-life serial killer Dennis Nilsen in ITV's Des: ‘There are lessons to be learnt from this story’

Doctor Who and Broadchurch star David Tennant tackles one of the most infamous criminal cases in UK history as he portrays serial killer Dennis Nilsen in a new TV series.

The acclaimed Scottish actor, 49, takes the lead role in ITV’s brand new crime drama, Des, about the civil servant who murdered at least 12 boys and young men in London between 1978 and 1983.

The three-part series tells the story from a new perspective, following not just Nilsen but also the police investigation into the murders (led by Police Detective Peter Jay, played by Daniel Mays) and Nilsen’s biographer Brian Masters (played by Jason Watkins).

Des also delves into the emotional impact of Nilsen’s terrible crimes, not just on the victims but on their families too.

Tennant answered our seven burning questions about the show, including how he got involved with the project, what appealed to him about playing Dennis Nilsen, the pressure of portraying a real-life person, and the research he did to get into character… 

1. Who was Dennis Nilsen?

David Tennant: Dennis Nilsen was a serial killer who murdered up to 15 men in London from 1978 to 1983. He was born in Fraserburgh, Scotland. He was part of the army and eventually the Police Force. He found his way down to London, where he worked as a civil servant at a Job Centre in North London. 

To the outside world, Dennis was a normal, even boring, individual; but he had a very dark, secret life. He took men to his flat, murdered them, and kept their bodies under his floorboards. Eventually, he would remove their bodies and burn their remains in his back garden. 

He finally got caught when he moved to Muswell Hill. He was now on a top-floor flat trying to flush human remains down the toilet. This ended up blocking the drains and led the police to his door. Without that, who knows how long he might have continued because no one had suspected him of anything, and it was a huge shock to those who knew him.

2. Can you tell us the story of ITV's Des?

Our story really begins when Nilsen gets caught. That is our starting point. So in a sense, we are with the police as they discover this extraordinary case that nobody even knew was going on. A lot of these men may have been registered as missing but some weren’t particularly missed. That’s because Nilsen, to an extent, preyed on the vulnerable or disconnected. 

A lot of Nilsen’s victims either didn’t have families who were missing them or they had lost touch with loved ones and had disappeared into London society. Therefore, Nilsen was managing to go undetected.

Our story begins as his crimes are uncovered for the first time. The police officers can’t quite imagine what they’ve stumbled on as they first think that Nilsen has secreted one body in his flat. 

It was only when they looked in a bag full of remains from his wardrobe that they suspected there may have been more than one victim. They later question Nilsen on how many victims there were - to which he answered as many as 15 or 16. This of course is the beginning of an unprecedented murder case where the only genuine witness is the murderer himself.

The extraordinary part of the story is when Nilsen is caught. He never tried to do anything apart from confess and almost all the information police gained for the investigation was directly from Nilsen. The one thing he did not offer up - either because he did not know it or choose to have a selective memory - were the victims’ names. He knew very few of their names, which was an obstacle for the police as they needed to charge him with specific murders.

3. How did you get involved with the series?

I read Brian Masters’ book Killing for Company many years ago and I used to live in North London, so I’ve always known about this story. I’ve heard of a few Nilsen projects over the years and I had even been briefly involved in another Nilsen project, which never got past the development stage. 

I have been involved in this project for a while. I read Luke’s script a few years ago after a mutual friend shared it with me. Then when I was filming the third series of Broadchurch, our director Lewis Arnold spoke about a Nilsen project which was the same project, so we talked about it and I was involved from that moment on.

4. What appealed to you about playing someone like Dennis Nilsen?

As an actor you are always looking at what makes the human condition and why humans do what they do. In this case, it was about looking at what makes human beings do something like this. How could a human be capable of this? It was about joining the dots and looking at whether it was an illness or was it just darker impulses? From an acting point of view, that’s intriguing.

There is also a story to be told about the victims and why people fall through the cracks of society. Plus, how Nilsen could murder so many men without being noticed.

Additionally, there is also a story about Peter Jay [Daniel Mays, below] and the times in which the crimes occurred. The case was in the 1980s and the murders were considered ‘gay murders’, and so, they were sort of compartmentalised in a way that society didn’t need to deal with them. So there is a lot going on in this story. 

It’s a very bleak story with a lot of actual real-world damage caused by this man, but I think as a society we have to try to understand why this happened and how to not have it happen again.

Nilsen shouldn’t have been allowed to murder all those people. Somebody should have noticed what was going on a lot earlier than they did, and that’s partly to do with the times and partly to do with how we as a society don’t look after all our members.

5. Is there any extra pressure in playing a real-life person like Dennis Nilsen?

We are telling a story that is still within living memory, so there are members of the victims’ families who are still devastated by what Nilsen did and there are the victims whose lives have ended because of Nilsen. So we must be sensitive and aware of that. Our producers and ITV were always aware and it is something that nobody takes lightly. 

We are all aware of the responsibility of telling this story, and I think it is right to tell this story as it’s a part of who we are as a society and as humans. The last thing we want is to make anyone feel exploited and we have been very careful to not do this at every stage of the development.

Everyone is aware of the real-life damage of this story and I hope that people will see that we have told this story responsibly.

6. What research did you undertake to portray Dennis Nilsen?

There was a lot that has been written. Some of it is well written and some of it is quite trashy. So it was about separating the wheat from the chaff. Brian’s book was also a source. I met Brian [played by Jason Watkins in the show, below], as well as police officers at the time and other people involved in the case. 

There is also some footage of Nilsen. The story was big at the time, so you have to try to sift through that and look at what is useful and what isn’t.

Playing a real person often means that there are a lot of resources available to see what he looked like and how he moved. And you do not necessarily copy that - as it’s not about doing an impersonation - but it’s about witnessing how they existed.

7. What do you hope people take away from watching Des?

There are clearly lessons to be learnt from the Dennis Nilsen story. It does not mean we are going to eradicate aberrations of psychology like Nilsen. Unfortunately, now and again a human being is so damaged that they commit these terrible acts. But to deny that or to not tell the story of those people is to pretend that it did not happen and I think that telling this story is both a witnessing and confronting of that. 

To understand what happened is also important. I am not for a second saying we should empathise with Nilsen or forgive what he did, but I think it’s important to see that people are capable of malfunction so grotesquely and it is a part of the human condition.

Watch the Des trailer

 Des starts Monday, September 14 at 9pm on ITV.