Nick Reiner, son of renowned filmmaker Rob Reiner, reportedly “stormed off” following a heated exchange with comedian Bill Hader at Conan O’Brien’s holiday gathering on Saturday, mere hours before a tragic double homicide occurred.

On Sunday, Rob Reiner, 78, and his spouse Michele, 70, were discovered brutally murdered in their Los Angeles home. Later that day, Nick was apprehended in connection to their deaths.

According to TMZ, the party turned tense after a “very loud argument” between Rob and Nick, with attendees noting Nick’s erratic behavior. His history of alleged aggression and substance issues was well-known among those present.

A source revealed to NBC News that Nick disrupted Hader during the event, bristling when the Saturday Night Live star remarked that he was “in the middle of a private conversation.”

Following Hader’s remark, Nick reportedly paused, stared intently, and then abruptly left the scene.

The unsettling interaction concerned other partygoers, the source added.

Rob Reiner’s son Nick Reiner (right with his father in 2016) allegedly ‘stormed off’ after getting into a tense chat with comedian Bill Hader at Conan O’Brien’s Christmas party on Saturday – hours before the double murder 

The couple was killed inside their mansion in Brentwood, a ritzy neighborhood in Los Angeles

The Daily Mail has contacted representatives for O’Brien and Nick’s attorney Alan Jackson for comment and has yet to hear back.

A representative for Bill Hader declined to comment. 

Rob reportedly brought Nick to O’Brien’s holiday party to ‘keep an eye on him’. 

Guests at the A-list packed holiday party said Nick displayed ‘antisocial behavior’ including staring at attendees.

At the party, sources also told People that Nick was ‘acting crazy’, and ‘kept asking people if they were famous’. 

The late couple’s daughter Romy, 28, who lives across the street from their home in LA’s ritzy Brentwood neighborhood, made the grim discovery of their dead bodies the following afternoon.

Nick, who lived in his parents’ guest house, was arrested for allegedly fatally stabbing them in their bed on Sunday night after he checked into a motel close to Santa Monica pier.  

Police reportedly raided the hotel room and found a shower ‘full of blood,’ blood all over the bed and the windows blacked out with the bedsheets.

Nick, who lived in his parents’ guest house, was arrested for allegedly fatally stabbing them in their bed on Sunday night; Rob and Michele pictured in March 2025

The Reiner family pictured all together

Nick Reiner, 32, (pictured in September 2025) allegedly ‘interrupted Hader’ at the party and was  left annoyed when the SNL comic told him he was ‘in the middle of a private conversation’

Nick’s first court hearing was set for Tuesday morning at the Clara Shortridge Foltz Criminal Justice Center, but was delayed because he was not medically cleared to be transferred from the jail to the courthouse, according to Jackson. 

Jackson told reporters outside the courthouse that he did not know what the medical issue was, but he said Nick will not appear before Wednesday. 

Nick remains in custody at Men’s Central Jail in Los Angeles. 

He was arrested several hours after his parents were found dead in their home in the upscale Brentwood neighborhood of Los Angeles on Sunday.

The couple were found in bed with their throats cut and may have been asleep when they were murdered, a source close to the investigation claimed to the Daily Mail. 

The gruesome detail could help establish a timeline of the killings. Investigators have not yet offered any potential motive for the murders.

His attorney has made a career of representing high-profile clients, including CEOs, celebrities, NBA players and foreign royals.

Among Jackson’s most famous clients was Harvey Weinstein, whom he represented during his sexual assault trial in Los Angeles. A jury convicted Weinstein in 2022.

He represented Kevin Spacey when he was accused of sexually assaulting an 18-year-old man in Massachusetts.

The source claimed after Hader’s alleged comment: ‘Nick just stood there and stared before storming off’ (O’Brien pictured above in 2019)

Conan O’Brien seen with Albert Brooks and Rob Reiner in 2024

Jackson, known for his assertive court-room style, challenged the accusations from the accuser and prosecution. The charges against Spacey were ultimately dropped.

He most recently represented Karen Read, who this year was acquitted of murdering her boyfriend in Massachusetts after a mistrial and hung jury.

Jackson was a central figure in the HBO documentary about the Read case. 

Rob Reiner was the Emmy-winning star of the sitcom All in the Family who went on to direct films including When Harry Met Sally… and The Princess Bride. He was an outspoken liberal activist for decades. 

Michele Singer Reiner was a photographer, movie producer and advocate for LGBTQ+ rights. They had been married for 36 years.

Three months ago, Reiner was photographed with his parents and siblings at the premiere of his father’s film Spinal Tap 2: The End Continues.

In the wake of Rob Reiner and his wife’s deaths,  O’Brien stationed an armed security guard outside his luxurious $20million Brentwood estate

The comedian appears to be heightening precautions amid the shocking tragedy that followed his star-studded Christmas party

He had spoken publicly of his struggles with addiction, cycling in and out of treatment facilities with bouts of homelessness in between through his teen years. 

The father and son explored – and seemed to improve – their relationship through the making of the 2016 film, Being Charlie.

Nick co-wrote and his father directed the film about the struggles of an addicted son and a famous father. It was not autobiographical but included several elements of their lives.

‘It forced us to understand ourselves better than we had,’ Rob Reiner told the AP in 2016. ‘I told Nick while we were making it, I said, “You know it doesn’t matter, whatever happens to this thing, we won already”.’