Thrust into an unexpected position, nothing could have truly prepared him for this moment.

Yet, Jake Reiner, son of esteemed filmmaker Rob Reiner and his wife Michele, has emerged as the vital force uniting his stunned family, according to a source speaking to the Daily Mail.

The 34-year-old, who transitioned from journalism to acting, has become an emotional anchor for his grief-stricken younger sister Romy, 27, as they confront the horrific loss of their parents.

“Jake has had to adopt a fatherly role,” the source disclosed.

His guiding principle is “family first,” a value deeply instilled in him by Rob and Michele, who always emphasized its importance to their children.

The Reiner family was cast into a harrowing reality after the celebrated director, aged 78, and his photographer wife, 70, were tragically found stabbed to death in their Los Angeles home on December 14.

The couple’s troubled younger son Nick, 32, will spend Christmas behind bars, having been charged with two counts of first-degree murder.

Left to pick up the pieces are siblings Jake and Romy – who is set to turn 28 on Saturday.

Jake Reiner, Rob and Michele Reiner’s older son, is pictured for the first time since the tragic murders of his parents, while grabbing coffee with his girlfriend Maria Gilfillan in California on Tuesday 

The seemingly happy family were due to celebrate the holidays and youngest daughter Romy’s 28th birthday together this week before the couple was brutally murdered at their home

As heavy rainfall hammers down on the West coast, the dazed clan have gathered at a private Southern California beach house this week.

‘They are sheltering from the storm – both literally and emotionally,’ the Daily Mail’s insider revealed.

Also present are Michele’s sisters Suzanne and Martine, Romy’s boyfriend Alex Silberberg, 29 – and Jake’s partner Maria Gilfillan, 29, who was pictured with him this week in exclusive Daily Mail photos. 

‘They all felt it was really important to come together as a family for the festive week and to mark Romy’s birthday, however subdued the celebrations,’ the source added.

At the center of the family’s quiet rallying effort has been actor Jake.

As the eldest of Rob and Michele’s brood, it fell on him to attend Los Angeles’ Mount Sinai Mortuary on Friday to collect his parents’ cremated remains.

Rob and Michele’s death certificates, released by the LA County Medical Examiner’s office this week, revealed the couple died from ‘multiple sharp force injuries’ caused ‘with a knife, by another’. 

Exclusive Daily Mail photos show a somber Jake, 34, dressed casually in sweat pants and an LA Dodgers cap during the outing 

The LA County medical examiner noted that the slain couple’s remains were given to their older son and have been cremated 

Jake’s partner Maria Gilfillan, 29, has been spending time with the Reiner siblings amid the tragedy 

Jake and Romy have been working through the logistics for an upcoming memorial service expected to draw many of Rob’s showbiz pals.

Jake has also been keeping an especially close watch over Romy who was left traumatized after finding her father’s dead body.

Romy, an actress and writer, went to check on her parents after their massage therapist was unable to reach them.

She reportedly fled the Reiners’ $13.5 million Brentwood, LA, mansion without noticing her mom was also dead but a paramedic later delivered the grim news.

‘Jake is determined to get his sister through this,’ the source said. ‘It’s an enormous burden, but he’s the oldest and he sees it as his duty.’

Jake was born in May 1991, two years after Rob married film producer and political activist Michele.

A graduate of Syracuse University, he spent a decade building a career as a charismatic broadcast journalist, reporting for cable stations in Rochester, New York, Houston and Los Angeles.

Sources tell the Daily Mail Jake has stepped in as the emotional lynchpin for his traumatized younger sister Romy, 27, in the wake of the tragedy

Romy and Jake are now not only forced to grieve the devastating loss of their parents, but must confront the grim reality that their brother Nick (center) is accused of their murders

He later followed in his father’s footsteps by landing acting gigs in a string of television shows and movies including Curb Your Enthusiasm and sci-fi epic For All Mankind.

One role involved Jake playing a reporter interviewing Lyle Menendez in the Netflix docu-drama Monsters: The Erik and Lyle Menendez Story.

The Menendez brothers famously murdered their parents, entertainment executive Jose Menendez and wife Kitty – a shocking crime not dissimilar to the one Nick Reiner stands accused of.

Jake is also co-host of The Incline, a podcast dedicated to the LA Dodgers baseball team, another passion he shared with his father.

‘There’s nothing like the ballpark,’ Rob told People magazine in 2023. ‘My dad was a huge, huge baseball fan. He passed it onto me, and I passed it onto Jake.’

But if Jake was viewed as the golden boy of the Reiner family, Nick was anything but.

Jake graduated from Syracuse University and spent a decade building a career as a charismatic broadcast journalist, at one point reporting for CBS LA 

The LA County Medical Examiner ruled Rob and Michele Reiner’s deaths homicides, caused by ‘multiple sharp force injuries with a knife by another’

Nicke battled years of drug addiction, had at least 17 stints in rehab and a history of violent outbursts.

Hours before the alleged murders, he was seen arguing furiously with his father at comedian Conan O’Brien’s Christmas party.

Even friends familiar with the couple’s desperate efforts to help their wayward son were stunned by Nick’s hostility.

‘I’m petrified of him,’ Rob is said to have confided to fellow guests.

‘I can’t believe I’m going to say this but I’m afraid of my son. I think my own son can hurt me.’

According to TMZ, Nick had been diagnosed with schizophrenia, but recent tweaks to his medication saw him become ‘erratic and dangerous’, according to the outlet. 

Nick is yet to enter a plea but is reportedly considering an insanity defense.

Romy Reiner and her boyfriend Alex Silberberg

LAPD call records obtained by the Daily Mail revealed police had been called to the couple’s Brentwood mansion at least six times since 2013

Speaking outside court this week, his attorney Alan Jackson said: ‘There are very, very complex and serious issues that are associated with this case. These need to be thoroughly and very carefully dealt with.

‘We ask that throughout this process you allow the system to move forward in the way that it was designed to move forward, not with a rush to judgment.’

Jake and Romy responded with a joint statement of their own.

‘Words cannot even begin to describe the unimaginable pain we are experiencing every moment of the day,’ the siblings said.

‘The horrific and devastating loss of our parents, Rob and Michele Reiner, is something that no one should ever experience.

‘They weren’t just our parents; they were our best friends. We are grateful for the outpouring of condolences, kindness, and support we have received not only from family and friends but people from all walks of life.’