Rob Reiner's son Nick's long struggle with addiction and volatility comes into focus after parents’ deaths

From addiction struggles to violent outbursts, Rob and Michele Reiner's son, Nick, has had his share of battles throughout the years. On Monday, the 32-year-old was arrested and booked on suspicion of murder in the horrific deaths of his parents — who were found dead at their Brentwood, Calif., home on Dec. 14. 

Reiner was initially booked on $4 million bail, but records now show he is being held without bail. On Monday, he was transferred to the Twin Towers Correctional Facility, according to the Los Angeles County Sheriffs Department. 

Investigators believe Rob and Michele suffered stab wounds, according to a law enforcement official who spoke to The Associated Press on the condition of anonymity.

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"This is not the first time their son has been violent," a longtime neighbor told the New York Post. "I know of another incident a few years back with Nick, but I won’t say more than that. I just never thought it would ever get to this point."

"Rob was always heartbroken that his son couldn’t beat his addiction," the neighbor continued. "I know they wanted him to get help, go to rehab, but he wanted to get help while at home — he did not want to get treatment at a facility."

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"And I know they have argued about that for years. Nick has had demons for the longest," they added. "It is such a nightmare. The whole thing is a tragedy."

Another neighbor told Fox News Digital that Nick had gone to rehab years ago, and she thought he was "back to normal."

"Years ago, when he was young, he was on heroin and cocaine, and he went to rehab and did well and was apparently back to normal, but obviously, that wasn't the case," Maryanne Lewis, who has lived in the Reiners' neighborhood for over 50 years, said. "I heard nothing about him recently."

Nick had been open about his struggles in the past. 

In 2015, Nick and Rob released a semi-autobiographical film titled, "Being Charlie" — a movie loosely based on Nick's real-life experience with addiction and recovery.

"It forced me to have to see more clearly and understand more deeply what Nick had gone through, and I think it forced him to see things that I experienced during this process," Rob said during a 2016 interview on BUILD, YouTube’s live interview series. "It brought us closer together."

"The whole process, for me, made me understand him a lot more. And I think it made me a better father. Hopefully, it did. If your kid is going through a rough time, the parent, your main job is to keep your child safe. I felt at a loss."

Nick gave an interview about "Being Charlie" alongside his family at the Toronto Film Festival in 2015, saying his decision to quit heroin was driven by a practical realization.

"I got sick of it. I got sick of doing that," he told the Times. "I come from a nice family. I’m not supposed to be out there on the streets and in homeless shelters doing all these...things."

During that same interview, Rob spoke candidly about how he handled his son's addiction at the time. 

"When Nick would tell us that it wasn’t working for him, we wouldn’t listen," he said. "We were desperate, and because the people had diplomas on their wall, we listened to them when we should have been listening to our son."

"We were so influenced by these people," Michele added. "They would tell us he’s a liar, that he was trying to manipulate us. And we believed them."

Despite their differences, the film ultimately bonded father and son. 

"To be honest, by the time we got to the point of making the movie, it didn’t matter if we actually did," Reiner told the Times. "Because our relationship had gotten so much closer."

During an appearance on the "Dopey" podcast in 2018, Nick opened up about a time when he became violent while using meth in his parents' guest house. 

"I went 10 rounds in my guest house," he shared. "It’s not much of a story. 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 some things in my guest house."

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"Everything in the guest house got wrecked," said Nick, who admitted there was "no logic" behind his outburst. 

According to TMZ, Rob and Nick allegedly got into a "very loud argument" while attending Conan O'Brien's Christmas party one night before the murders. 

"Nick was freaking everyone out, acting crazy, kept asking people if they were famous," a source told People. 

A representative for O'Brien did not immediately respond to Fox News Digital's request for comment. 

A source told Page Six that Nick "really resented his dad" and "hated himself for not being as talented, prolific or beloved as his dad or grandad."

WATCH: ROB REINER'S SON ARRESTED IN CONNECTION WITH PARENTS' MURDER 

A family spokesperson initially confirmed the deaths to Variety, saying, "It is with profound sorrow that we announce the tragic passing of Michele and Rob Reiner. We are heartbroken by this sudden loss, and we ask for privacy during this unbelievably difficult time."

Following the initial investigation into the Reiners' homicides, authorities determined Nick was "responsible for their deaths."

Nick was located and arrested at approximately 9:15 p.m. Sunday. He was booked on suspicion of murder and is now being held without bail, according to the Los Angeles Sheriff's Department.

The case will be presented Tuesday to the Los Angeles County District Attorney's Office, the LAPD confirmed in a release.

Rob and Michele had three children together: Jake, Nick and Romy.

Fox News Digital's Tracy Wright, Lauryn Overhultz and Larry Fink contributed to this report.