Taking on the role of Edmund Kemper, a real-life serial killer who murdered 10 people from the mid-1960s through the mid-1970s, pushed Cameron Britton’s career from occasional guest star status to captivating supporting player. In the Netflix drama that Joe Penhall adapted from John Douglas and Mark Olshaker’s book, Britton’s scenes were mostly confined to small interrogation rooms as detectives interviewed him about his crimes in order to learn the inner workings of a killer’s mind. Britton calls the experience, which also included working with prolific director David Fincher, an “almost spiritual” one. “Episode 2” was the first time the audience got a glimpse at Britton’s take on Kemper, becoming both captivated by his affectations and perhaps concerned by how closely they were connecting with a killer.

Britton: “When I received the audition script I had never heard of Ed, and the description in the email did not even say that Ed was a real person. What I found interesting was that when I picked up the page and started reading the dialogue, for some reason, I could just tell this was a real person. So I looked up his name and found him on YouTube and went from there. Every single thing that I have learned about him since has been unendingly fascinating to me.

“I was lucky enough early in the process to not want to make an imitation and that’s something that David did not want either. So it allowed me, when watching interviews with him, to capture his essence and then just let everything else come organically and instinctually to me. So you sort of get a mix of what Ed Kemper was like and then the artistic expression that I found.

“This character is trying to hide his true self from everyone, so the audience needs to be able to see the true self and that he’s hiding it. So in my process, what I do is fill myself with dark impulses and then sort of create a second character. There’s Ed and then there’s the character Ed’s created to seem normal.

“Before shooting Ed my hair was down to my shoulder blades and I had a big beard. Hair and makeup and costumes went into every detail possible to be really authentic — [slicking back] my hair, which is very curly, darkening my eyebrows and [putting] my prescription in those glasses. It helped dramatically with the performance to be able to look in a mirror and not see yourself.

“I think what makes Ed Kemper so interesting is the way he phrases things and how insightful he is. It’s enough to just simply transcribe it at times. The rest of the script was Joe Penhall, and usually as an actor there’s a line or two in a script you don’t care for or that you want to re-look at, but with this script there was none of that. I loved every single word.

“After the first day [of shooting] I was pretty tired, but what made it through the week and what made me full of energy was all of those takes. There’s something incredible about sitting in a chair and just doing what you love until it’s time to go home.

“Mostly between takes [Jonathan] Groff and Holt [McCallany] and I were singing show tunes. It was a really dark subject matter, so it was really nice to have light, fun energy between to remember that this is acting. As an actor you need to enjoy what you’re doing to really do it.

“Sometimes Ed just lingers. It’s hard to get out of that energy. That’s the hard part — with many characters I’ve done, sometimes I feel them sprout up when I’m driving and I want to do them, but with Ed I ignore those impulses because if you just have dark thoughts all day, they become habitual. But that being said, I very much enjoy that headspace because, creepy as it is, there’s a control and a power that comes from being this monster.”