Cooper Koch 'Listened' to Videos of Erik Menendez 'Every Night Before I Went to Bed' to Prep for Monsters Role

Cooper Koch wanted his version of Erik Menendez to be as true to life as possible.

The 28-year-old actor played the younger of the two brothers in Monsters: The Lyle and Erik Menendez Story, and he admitted just how far he went in his preparation for the role in a sit-down with Sam Nivola for Variety‘s Actors on Actors.

“I listened to him every night before I went to bed,” Koch said when the White Lotus star asked if he had watched “videos to try to impersonate the way [Erik] speaks.”

“I had him on in the car when I was driving,” he continued of Erik, who was 18 years old when he and his brother Lyle killed their parents, Jose and Kitty Menendez, in 1989. “I really did want to get his voice and mannerisms, because they all further support that he was being sexually abused by his father.”

“I know there’s so many perspectives, but I always wanted the audience to sympathize with him,” he added.

Both Erik and Lyle have continued to claim that their father sexually abused them both for years, which led to them killing him and their mom, who allegedly also knew about the abuse.

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Since Monsters‘ September release, Koch has been clear about how passionate he is about the brothers’ case and vocal in his support of their resentencing efforts.

“I just felt this insane cosmic thing that was like, ‘I have to play this part,'” he told Nivola, 21, of playing Erik in the Ryan Murphy series. “And this immense empathy. There are all of these weird parallels. We both went to Calabasas High School.”

Shortly after the show premiered, Koch got to visit Erik and Lyle in prison alongside Kim and Khloé Kardashian and their mom, Kris Jenner. He told PEOPLE it was an experience he was “so nervous” for.

“I had spoken to both of them, so I knew we already kind of had a camaraderie, and they knew where I stood. I told them I supported them and I believed them. I had a feeling they were going to welcome me with open arms, but still so nerve-racking to meet someone who you’ve been listening to and are inspired by.”

He said there was “an immediate connection” when he arrived at the Richard J. Donovan Correctional Facility in San Diego. “I got to hug both of them, and I sat next to Erik in this circle with all the other incarcerated individuals who were telling their stories, and they were both so kind. They’re amazing people.”

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Monsters: The Lyle and Erik Menendez Story can be streamed on Netflix.

If you or someone you know has been a victim of sexual abuse, text “STRENGTH” to the Crisis Text Line at 741-741 to be connected to a certified crisis counselor.