'My Friend Dahmer' Star Ross Lynch on Leaving Disney Channel to Play a Serial Killer (Exclusive)

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Ross Lynch just returned home to L.A. after a six-week tour of Europe with R5, the pop-rock family band he formed with his two older brothers, his little sister and a childhood friend. The band's star has been on the rise since Lynch broke out as a tween star on Disney Channel's Austin & Ally and in the Teen Beach Movie franchise. Now 21, Lynch is promoting his first movie since his contract with the Mouse House ended: My Friend Dahmer, out now. Lynch plays the infamous serial killer, Jeffrey Dahmer, as a high school outcast in the years before he would commit his first murder and go on to kill and sometimes cannibalize 16 other men from the late '70s to the early '90s. Lynch wasn't born until 1995, though, a year after Dahmer's death, so he had no idea who Dahmer was until receiving the script.

"When the script came to me, they were like, 'Hey, this is about the serial killer, Jeffrey Dahmer,' and I was like, 'Oh, I don't know who that is,'" Lynch laughed while discussing the film with ET. "It's the 21st century, so I went straight to Google and pretty much read his whole Wikipedia page right then. I was fascinated and shocked and terrified, all at the same time."

ET: After you'd read all of the truly horrifying things that Dahmer did -- murder and necrophilia and cannibalism -- how do you look past the monster that he was to find the human you play him as?

Ross Lynch: You know, I tend to empathize with people, just in general. Even like the a**hole at school or even-- That's just sort of who I am. I have, like, a no judgment policy, sort of. [Laughs] Granted, at times, that gets a little hard. I just think, in general, I'm not a really judgmental person. And in my eyes, the script really paints this empathetic view of Jeffrey Dahmer. I really wanted to make people feel this conflicted way towards Jeffrey Dahmer towards the end of the film, that was part of my goals in taking on this role. He starts out as this troubled teenager and really, throughout the film, we see him losing his humanity.

What do you think we achieve from humanizing Dahmer?

I think people will more ask the question of, "How did this happen?" That's the whole question with every serial killer, "Is it nature or nurture?" And I think everyone could be a little more, you know, gentle with each other, especially in high school. In the '70s, granted, it was a different time and it was a lot more-- There was nothing going on and kids were just doing whatever they wanted because they had nothing else to do, and it was probably a more harsh time, especially in high school. But, you know, just ask the question of, "How did this guy come to be this way?"

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I assume you have to get into a certain mindset and go to some dark places in playing Dahmer. How would you get there?

For me, personally, it was all about just being in that moment. In the costume, in the surrounding-- You know, we shot in his actual home. Just being in that environment and saying those words that he said and having my body language that way, really just immersing myself in what I thought Dahmer was at that age. It's my first time doing anything like this, so I really was kind of experimenting with myself and going through all sorts of different thought processes and, depending on the different actors that I was working with, feeding off of them and just really trying to do the best work that I could do.

You mentioned the body language, and you play Dahmer in a lumbering, hunched manner. What went into developing that physicality?

It wasn't all that intense of a process, actually. I had this one reference video that I would watch very often on set. In this video, Dahmer walks into the interview with that posture and he's shuffling his feet. It's really shocking when you see it, because even in the film, you could say, like, "Oh, it's over-exaggerated," but that's actually how he walked. We had people come on set that went to high school with him, because they had heard we were making a film about Jeffrey Dahmer, and they would show up and they would say, "Oh my gosh, you resemble Jeffrey Dahmer to a tee." They would say, like, "Your walk and everything looks exactly like him." But, really, I just got that from this video that I would watch all the time, and I come from a dance background, so it really wasn't that hard to recreate it.

Ross Lynch in 'My Friend Dahmer'

The movie is adapted from John Backderf's graphic novel about actually being friends with Dahmer. Did you have a chance to talk with the real Derf (played onscreen by Alex Wolff) about his experiences?

Yeah. Me and Derf, I've seen him all over the place, like, in various festivals and Comic-Cons, things like that. And before we started filming, we had a chance to sit down at dinner and we talked pretty extensively about his relationship to Dahmer and sort of what he thinks prior to knowing he was a serial killer and after knowing he's a serial killer...because what I thought was interesting is in Derf's mind, he had two different realities of high school. He had the reality of just his boring high school in Akron, Ohio, and then he has the reality of going to high school with a serial killer. So, we did get a chance to sit down prior to filming and talk about his experiences and how he knew Dahmer and really how Dahmer was acting at that age.

Was there one main takeaway you took from those discussions?

There was one question that I had [which] was, "What was Dahmer's eye contact like?" Because I think you really can tell a lot about a person from how they move. A lot of people say actions are stronger than words and I think, in acting, this is a very accurate thing. So, I really wanted to get that down.

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What did Backderf remember Dahmer's eye contact being like?

He said it was shifty. He wouldn't hold a gaze very long. He wasn't a very confident guy, really. But there were times when he would turn on the chemistry or when the charismatic Dahmer would come out. There was one scene where I get a chance to show that side of him, where he's asking the girl to the prom, where he's kind of looking deep into your soul. [Laughs] So, there's different sides of Dahmer and he definitely can turn on that charismatic thing where he convinced people to come with him, you know?

After getting into character, how would you shake off Dahmer at the end of the day?

I actually had this mousse in my hair, this colored mousse because they wanted to make my hair a little bit darker. And my way of shedding Dahmer was I would go to the shower and I would sit in the shower for quite a long time and watch this mousse drain out of my hair and go into the drain. And it was kind of symbolic for me of shedding Dahmer for the day.

My Friend Dahmer Poster

The majority of your work ahead of My Friend Dahmer has been with the Disney Channel. Did this feel like a purposeful move to get people to see a different side of you, to see a more adult side?

Yeah, I definitely, definitely had that in mind. But if you strip all that away, I still would have been more than excited to do this film. That was definitely a factor that really was exciting to me, but it was also a great script and [director] Marc Meyers, he had such a vision and he was such a joy to work with and a great guy. All around, it was just a good experience.

What do you think your fan base is going to think of the movie?

You know, they've actually, like, tweeted me quite a bit, because we've had trailers and posters and whatnot come out, and it's all been super positive! Everyone is really excited about this film and I think people, in general, like to see people succeed and people like to see growth. So, everyone is super excited.