Ex-Disney star channels murderer

He’s an all-American blond cutie who had a hit Disney Channel show, “Austin & Ally,” and sings in a band, R5, alongside siblings Riker, Rocky and Rydel. So, naturally, Ross Lynch’s eyes lit up when the role of Jeffrey Dahmer rolled around.

“I liked the fact that it was going to shock a lot of people,” the 21-year-old actor says. He’s already gotten advance acclaim for his portrayal of the serial-killer-to-be in “My Friend Dahmer,” which sees Lynch slump-shouldered, speaking in a monotone and doing some disturbing stuff as the young Dahmer, whose hobbies included dissolving roadkill in jars of acid.

“Certain scenes are creepy,” Lynch says. “A scene near the end with me and Derf in the car — once we were done shooting that, Alex [Wolff, who plays Derf] and I thought we were gonna throw up. It was really strange. The crew was creeped out, too.”

Lynch, who lives in Los Angeles, says he watched videos of interviews with the real Dahmer and read Derf’s graphic novel for research. “As far as the mindset goes,” he says, “it was really a lot about being in costume and having the glasses on — and being in his actual childhood home.” The film was shot in Dahmer’s hometown and was able to film scenes in his house (now owned by a friend of Derf’s).

Lynch says he developed a sort of empathy for Dahmer: “I go back and forth, thinking maybe he could have been helped,” says the actor, whose next film will be a comedy. “Someone could have intervened, and helped him . . . But then, I also think, maybe he just had a few too many screws loose.”