John Simm on ITV’s Code of a Killer

John Simm plays Alec Jeffreys in ITV’s gripping new two part true story Code of a Killer which follows the attempts by scientist Jeffreys and policeman Detective Chief Inspector David Baker to bring a killer to justice using DNA for the first time.

Code of a Killer brings an extraordinary story to a wider audience?
“I didn’t know anything about it until I read the script. It’s an extraordinary and amazing story. Alec Jeffreys is an incredible man who made one of the most important scientific discoveries ever. It changed the way the police find criminals. What a story to tell. I think it will amaze people who don’t know about it. And, of course, it’s a true story.”

You met Alec Jeffreys during filming didn’t you?
“We met at a dinner in Leicester while filming scenes at the university and sat next to each other. Alec regaled us with scientific tales and wonderful stories. If anything, my admiration for him went up after meeting him. He’s a really lovely man.

“There were certain details I wanted to know. For example, what he did at the ‘Eureka Moment’. Did he jump up and down? How excited did he get? We had already filmed that scene and I think I got it fairly close to what he described. We discussed things in the script and how he first became interested in science.”

You also visited the actual laboratory at Leicester University where he discovered DNA fingerprinting?
“Alec showed me exactly where it happened on that Monday morning back in September 1984. It’s quite something to be there. You do get a real feeling of wonder standing there.”

And did you get to use any of his period scientific equipment in the drama?
“I did. I found out half way through using all this equipment that the pipettes and everything had Alec’s name on them. I thought the art department must have done that for the production. But most of it was the actual equipment, machines and material he used in his laboratory at the time. And I play with them trying to look as if I know what I’m doing. That felt really special.”

You grew a beard for the role to capture Alec’s look in the 1980s?
“I had enough time to grow it before we started filming. It was dyed as well – I had dyed hair and a dyed beard. I shaved it off when I got back at the end of filming.”

Did you do your own research on Alec?
“I watched him on YouTube and they sent me quite a lot of footage of him. I was interested in how he spoke then and how he moved around the lab. There was quite a bit of film of him being interviewed. I didn’t want to do an impression of him. I just had to get an essence.

“He is quite a character and he speaks differently to me. I studied his voice and taped snippets of it and put it on my phone as voice memos. So I’d have that on me all day and every so often I’d play him talking. Just to get the feel of him. His physicality and his manner.

“Although I, of course, wanted to meet him, I was glad that didn’t happen until we’d started filming because I didn’t want to copy him, especially now as an older man where he might have changed a little.”

Were you good at science at school?
“Not really. It’s one of the best things about this job. You get to pretend to be all sorts of different people. And it was a real honour to play Alec Jeffreys. The reason I took the job was because I realised the importance of what he did. To be able to play a real life genius, a legend of the science world, was the thrill for me.

“Like most people, unless you’re into science and know about it, I was pretty ignorant about the details before this. So it was great to go over it and learn. To discover what he actually did.

“The good thing about the script is the story of the DNA discovery is very clear and easily understood. And it’s quite amazing that it happened by accident. Then it just so happened a police detective called David Baker was looking for this killer in the same area, read the article about DNA, took a chance and was very brave.

“They are both incredible characters. Real life heroes. Hopefully the brilliance and bravery of these two men will be recognised by a wider audience.”

How would you sum up the relationship between Alec Jeffreys and David Baker?
“A lot of it has been dramatised to tell the Code of a Killer story. David was a visionary in terms of policing. He had the imagination to see how this might help them catch the killer at a time when they were running out of leads. It initially led to a young man who had confessed to one of the murders being released because the DNA test proved he was not involved and that he had given a false confession. David was a very brave man to stand by this new discovery and to trust Alec’s science.”

The drama is obviously very sensitive to the fact that at the centre of this story is the murder of two teenage girls?
“It was done with the full knowledge and support of the families and, of course, you have to be very careful. These are real people and real lives.”

Alec had concerns at the time about his personal safety?
“There was some concern the killer would know where he lived and Alec was the man who gave police the means to identify him. There were also people turning up outside his house after the DNA discovery. He was inundated with people asking for his help in immigration and paternity cases.”

It’s mind-boggling when you think how this discovery is now used around the world in so many ways?
“The ripples of the discovery he made continue to get bigger and bigger. It becomes more and more important as the world turns. I wasn’t into science before this but it seems since we’ve filmed this that DNA is in the paper every single day. Every time I look, DNA has done something else.”

Have you ever had anything approaching a ‘Eureka Moment’ yourself?
“Perhaps when I first tried acting. My first ever drama class when I was coaxed into going. It was Billy Liar. As soon as I started it and everybody went, ‘Oh, well that was pretty good,’ I thought, ‘Maybe I could do this?’ And every time I hear The Beatles.”

You’re reunited on screen with David Threlfall for the first time since you played Kendle Bains and Lenny Smart in the mid-90s’ BBC1 comedy Men Of The World?
“That sitcom wasn’t a big success but I thought it was quite funny at the time. David and I also sang the theme tune. I remember how much fun we had recording it. We’ve been good friends ever since.

“We can’t quite believe it’s taken this long to work together again. We’ve always been meaning to do something on stage and it almost nearly happened. It wasn’t the reason I took the job but it was a big factor. I thought, ‘Well, I’d love to work with David again.’

“He was one of my heroes when I was younger. I saw him play Smike in Nicholas Nickleby and he blew my mind in that. I’ve always been a huge fan of his. He is one of the greatest screen and stage actors this country has to offer and has been for a long time. David Threlfall is another genius.”

The use of DNA testing is so commonplace today but it is amazing to think this discovery was only made in 1984?
“It is quite incredible. You think it’s always been around. It’s closer to the Life On Mars era, really. Then making use of new computer data bases. All of that was in its infancy.

“It was a real privilege to dip into that world which was just incredibly fascinating. And to get the chance to meet Alec and spend an evening chatting with him is something I will never forget. He’s one of the most incredible men I’ve ever met in my life.”