Being Charlie executive producer Douglas Shaffer opened up about Nick Reiner's behavior on set of the 2015 film, claiming he seemed like a "gentle guy." In a new interview with People published on Thursday, December 18, Shaffer recalled his experience with Reiner, 32, at the time, noting that nothing seemed amiss with his demeanour at the time. "From my interactions with Nick, he seemed like a gentle guy," Shaffer told the outlet. Nick, who battled addiction and entered rehab from age 15 onwards 17 times before the film was released, cowrote Being Charlie, inspired by his struggles. The movie also followed the main character's relationship with his dad, which was loosely based on Nick and dad Rob Reiner's real-life relationship. Rob served as director for the film. What Is 'Being Charlie'? Rob and Nick Reiner's 2016 Film Explained "He was very open. You didn't see this inner rage or anything like that." Shaffer claimed. "He seemed just kind of calm, cool and collected, and he was young at the time. He was 22, but again, that's where it's just that this is a mystery." Rob, 78, and Michele Singer Reiner, 70, were found dead from apparent stab wounds in their Brentwood, California, home on Sunday, December 14. After being named a person of interest, Nick was later arrested and charged with two counts of first-degree murder. He faces life in prison without parole or the death penalty if convicted, and his arraignment is set for January 7, 2026. (Rob and Michele also shared kids Jake, 34, and Romy, 27. Rob was also the adoptive father of ex-wife Penny Marshall's daughter, Tracy, 61, from a previous relationship.) Speaking to People on Thursday, Shaffer divulged how another Being Charlie producer, Stephanie Rennie, reacted to the news of Rob and Michele's tragic deaths. "When she heard about the news, she said, 'It's a fever dream... it's just unfathomable,'" Shaffer told the outlet. "She didn't see it coming. Nobody saw it coming, and she was closer to those guys and it doesn't make any sense to her." Nick Reiner. (Photo by Michael Buckner/Variety via Getty Images) Shaffer added that he hoped mental health issues will be examined more closely in the wake of the tragedy. "It is a big talking point that sometimes just gets swept under the rug, and it affects a lot of people and it affects a lot of families," he said. "Obviously it affected this family, who seemed to have the perfect support system for their son, and you can only imagine other people who are dealing with that." In 2016, Rob spoke about working with his son on Being Charlie and shared how he believed collaborating on the project helped him get his head around what Nick had gone through. "The whole process for me, I can just speak for myself, it did make me understand him a lot more, and I think it made me a better father," Rob said at a Build Series event. "Hopefully it did. I don't know." Rob Reiner's Son Nick Praised His Parents in Past Interview: 'I'm Lucky' Rob also noted there "were disagreements" between the pair during the film making process, adding, "At times it was really rough [working on the film]," For his part, Nick said that making the film would sometimes feel "overwhelming" for him. "I really wasn't sure I wanted to do this," he said at the time. Despite Shaffer's descriptions, Nick himself had previously admitted to destroying his parents' guest house while in the midst of addiction. "It's not much of a story," Nick shared on an August 2018 episode of the "Dopey" podcast. "I got totally spun out on uppers - I think it was coke and something else - and I was up for days on end. I started punching out different things in my guest house." He added, "I went 10 rounds in my guest house. I literally punched the TV."