Rob Reiner's Troubled Son Nick's 'Dark, Twisted' Side Exposed by Former 'Family Guy' Colleague

A former co-worker of Nick Reiner has exposed his "dark, twisted" side they claimed to witness years before he was charged with murdering his parents, Rob Reiner and Michele Singer Reiner, RadarOnline.com can reveal.

Nick, 32, has been charged with two-counts of murder in connection with the fatal stabbings of Rob and Michele.

He was arrested on Sunday, December 14, hours after his younger sister Romy, 27, discovered the Princess Bride director's body inside the couple's Brentwood home.

More than a decade before Rob and Michele were fatally stabbed at their home after attending comedian Conan O'Brien's Christmas party, their son Nick, who has a history of drug addiction, appeared to be turning over a new leaf.

At the time, Nick was fresh out of rehab and started an internship working for the popular adult cartoon show Family Guy in 2014.

A production assistant has now come forward and, for the first time, revealed what they experienced working alongside the since-accused killer.

While reflecting on their time working together, the insider remembered Rob's son as being a "dark, twisted, kind of rough kid," according to Fox News Digital.

The production assistant claimed Rob helped his son get the job, and executive producers agreed to let him "hang out" because he was "trying to get back on his feet."

"Really, the executive producers were like, 'Just let him hang out. Like, he doesn't need to have a lot of responsibility. Don't let him touch anything. Just let this kid hang out, it's a favor to his dad, who we adore, and he's trying to get back on his feet,'" the source recalled.

The man further claimed because Nick was an intern and thus shadowed him for about four-hours every day, they became "really close."

He recalled Nick "struggling" with his then-newfound sobriety and how the director's son had been homeless for a period of time before going to rehab.

"He felt like this really raw kid," the source explained. "He had a very dark sense of humor. ... He was an introverted human, like he wasn't very loud. But he was also funny, and he felt very human."

"I remember really liking him, like I thought he was a really nice kid," he added.

While the insider recalled "really liking" Nick, he admitted the director's son was "dark" and appeared to be "not in the best mental health space" when he was interning for the television show.

"He was a really troubled kid," the man confessed as he recalled some of the crew members encouraging Nick to pursue stand-up comedy after learning he was interested in the possible career path.

The source said he told Nick his twisted sense of humor would work well as a stand-up comic – and reminded him his parents Hollywood connections could help land gigs.

Nick ended up taking the advice and performed a few sets at the legendary Los Angeles venue The Comedy Store, though the insider noted he never attended the gigs.

According to the source, Rob would drop off and pick up his son every day.

"It felt like the family wanted him to succeed, and it felt like they were constantly trying to set him up for success," he said. "And he was just this dark, twisted, kind of rough kid."