Cooper Koch in NYC (left); Lyle and Erik Menendez at Beverly Hills Municipal Court on March 13, 1990. Photo: Roy Rochlin/Getty; AP Photo/Nick Ut

Cooper Koch is officially a Golden Globe nominee and he can’t wait to tell Lyle and Erik Menendez the exciting news.

The 28-year-old actor gained instant stardom for his portrayal of Erik in Netflix’s Monsters: The Lyle and Erik Menendez Story, and after earning a Golden Globe nod for the role on Dec. 9, he tells PEOPLE that this is “a big moment” for the brothers.

“That’s what I’m most happy about, is that they get a big stage,” he says of the importance of the show being recognized. Monsters also scored a nomination for best television limited series, anthology series or a motion picture made for television and Javier Bardem was nominated for best performance by a male actor in a supporting role for his portrayal of Jose Menendez.

Koch is hopeful he’ll “hear from [Erik] or Lyle or somehow, something will get connected” as he “can’t really contact the prison” himself to initiate the conversation, but is eager to share the exciting news.

“I think they’re going to be so happy and excited,” he says of the brothers who were sentenced to life in prison without parole for the 1989 murder of their parents and recently received the support of the L.A. County District Attorney on their clemency request.

“That’s honestly something I’m most happy and excited about, that I get to have another moment to talk about them and advocate for them.”

Cooper Koch as Erik Menendez in ‘Monsters: The Lyle And Erik Menendez Story.’.Miles Crist/Netflix

Koch learned of his nomination from his bed in L.A. this morning, he says, after he “couldn’t sleep” in anticipation of this morning’s announcement.

“I woke up at like 4:45, and then my partner and I put it on YouTube and we started watching and then heard my name and screamed and hugged and freaked out.”

Bardem, 55, and his costar Ari Graynor were among the first to reach out to him, as was fellow nominee Colman Domingo. “He was like, ‘Congrats,’ and then I got to congratulate him back.”

Nicholas Chavez as Lyle Menendez, Cooper Koch as Erik Menendez, Ari Graynor as Leslie Abramson in ‘Monsters: The Lyle And Erik Menendez Story.’.Miles Crist/Netflix

Calling the nomination a “cherry [on top]” of such a meaningful project, Koch — who has been outspoken in his support of the Menendez brothers’ resentencing efforts — says it “feels really good” to be recognized.

“I’m not going to say, like, ‘Oh yeah, it’s whatever, blah, blah.’ Of course, I want it to be nominated for a Golden Globe. That’s amazing. But at the same time, it also doesn’t define my worth or my value,” he says. “I’m still proud of the show and proud of my work and stuff and I didn’t necessarily need [a nomination] to feel good.”

Javier Bardem, Nicholas Chavez, Cooper Koch and Chloe Sevigny at the L.A. premiere of ‘Monsters: The Lyle and Erik Menendez Story’ on Sept. 16, 2024.Gregg DeGuire/getty

It’s especially “nuts” for the actor given the company he’s in. “It’s crazy. It’s like the imposter syndrome is so real,” he says of his fellow nominees, which include Colin Farrell, Ewan McGregor, Andrew Scott, Richard Gadd and Kevin Kline.

“I’m so grateful and honored to be recognized amongst these people. It’s crazy,” he continues. “I still can’t believe that it’s happening — that it happened.”

Monsters: The Lyle and Erik Menendez Story can be streamed in full on Netflix and the Golden Globes will air live on Sunday, Jan. 5 at 8 p.m. ET on CBS and streaming on Paramount+.