EXCLUSIVE: Rob Reiner Hollywood Homicide Horror Latest — Iconic Director Had Time of His Life on Family Vacation in Devastating Final Posts… As His Ex-Junkie Son is Arrested

Tragic Rob Reiner grins while laughing and swimming with the daughter who found him knifed to death – in what would turn out to be his final family holiday before the filmmaking icon and his wife were slaughtered at their $13.5million mansion, RadarOnline.com can reveal.

The Oscar-nominated director and actor, 78, whose work helped define modern American cinema, took a sunshine trip with Romy Reiner, 28, weeks before he and his partner Michele Rainer, 68, were found lifeless in a bloodbath attack at their sprawling Los Angeles home, in a case that has shaken Hollywood and prompted an intense police investigation.

Sources say Reiner and his wife had their throats slit after a heated argument with a family member boiled over. And it's been reported Romy told cops a relative "should be a suspect" because they are "dangerous."

Rob and Michele were discovered inside their property on Sunday, December 14, authorities said – with sources saying Romy discovered their stabbed corpses.

The Los Angeles Police Department confirmed there were no signs of forced entry, while investigators continue to examine the circumstances surrounding the deaths.

The couple's son, Nick, has since been arrested.

Images from Reiner's final family trip were shared two weeks earlier by Romy, who is said to be "shattered" by her parents' brutal deaths.

In one post dated November 29, she showed herself and her father wading in the ocean, with Reiner wearing a baseball cap and smiling broadly.

In another, Romy wrote she was "thankful" for family and good health – a sentiment that now reads with painful irony.

A source briefed on the investigation said the injuries sustained by the couple were "consistent with a knife attack." Alan Hamilton, the LAPD's deputy police chief, added there was no indication of forced entry into the Reiners' home.

Born in the Bronx, Reiner spent more than five decades as a towering presence in entertainment. He first became a household name playing Michael 'Meathead' Stivic on All in the Family, appearing on the sitcom for eight years before moving behind the camera.

As a director, he delivered a remarkable run of films including This is Spinal Tap, The Princess Bride, and When Harry Met Sally. His 1993 courtroom drama A Few Good Men earned him an Academy Award nomination.

Through Castle Rock Entertainment, which he co-founded, Reiner also helped bring Seinfeld and The Shawshank Redemption to the screen. In later years, he continued acting, most notably as Jordan Belfort's sweary father in The Wolf of Wall Street, and appeared this year in The Bear and Spinal Tap II: The End Continues.

Tributes poured in from across film and politics in the wake of his and his wife's slaughter. Actor Ben Stiller said, "He made some of the most formative movies for my generation. He came out from behind a huge comedic shadow of the great Carl Reiner, and being a TV actor to being a great director who made an incredible run of movies. Spinal Tap is one of the best comedies ever made – and the list goes on. He was a kind, caring person who was really, really funny."

Josh Gad described Reiner and his wife as "two of the most kind and caring souls," adding their deaths were a "devastating" loss. David Furnish wrote online he and his husband, Elton John, had just worked with Reiner and his wife on Spinal Tap II, saying: "They were a joy to meet – and brilliant to work with."

Political leaders also paid tribute. Gavin Newsom hailed Reiner as a "big-hearted genius," while Barack Obama said the Reiners' lives were "defined by purpose." Former U.S. House Speaker Nancy Pelosi praised Reiner's creativity and humor, while Los Angeles mayor Karen Bass said his contributions to cinema "reverberate throughout American culture and society."