Nick Reiner, son of Rob and Michele, to be charged with murder after stabbing parents to death — what we know so far

Nick Reiner, the son of famed Hollywood director Rob Reiner, is set to be formally charged with the murder of his parents when he appears before a Los Angeles court on Tuesday, as per news agency AFP.

Nick, 32, was taken into custody earlier on Sunday after the bodies of his 78-year-old father Rob and 68-year-old mother Michele were discovered with multiple stab wounds in their Los Angeles residence, located in the upscale Brentwood neighbourhood.

The slain Hollywood couple were discovered by their younger daughter Romy Reiner, who immediately informed the police that the crime had been committed by a family member.

Reports at the time indicated that Nick, who has a history of substance abuse, had been taken in for questioning.

At the time, entertainment news outlet TMZ had also reported that a heated argument had ensued between Nick and his parents at a party.

Rob and Michele, along with Nick, had gone to attend comedian Conan O'Brien's Christmas party on Saturday night when the reported argument broke out.

The verbal spat between father and son was "very loud" as per TMZ, so much so that it was heard by multiple guests at O'Brien's party.

Family sources told the news outlet that Rob and Michele had departed the party following the argument. It wasn't clear whether Nick, too, had left with them.

Hours after the party, Rob and Michele's bodies were discovered.

Family sources cited by TMZ said that Michelle had confided to friends in recent times that she and Rob had been struggling to cope with Nick's behaviour, with the couple reportedly distressed over their 32-year-old son's mental health and alleged substance abuse issues.

While Nick has been arrested on homicide charges, it could escalate to a double murder charge on Tuesday.

That said, as of writing this, police had not said anything about a motive behind the killings.

Hollywood left stunned

The brutal killings of 78-year-old Reiner and his wife left the who's who of Hollywood stunned.

Oscar-winning actor Kathy Bates, who won the award as the star of Reiner's film Misery (1990), paid rich tributes to the departed director, who is known for several hits and critical favourites, including Cary Elwes and Robin Wright-starrer The Princess Bride (1987), Meg Ryan-starrer When Harry Met Sally (1989), and Tom Cruise-starrer A Few Good Men (1992).

Commenting on the director's killing, Bates said, "I loved Rob. He was brilliant and kind, a man who made films of every genre to challenge himself as an artist. He also fought courageously for his political beliefs. He changed the course of my life. Michele was a gifted photographer."

Actor Kevin Bacon, who co-starred in A Few Good Men alongside Tom Cruise also paid tributes to Reiner and his wife.

Recounting how Reiner gave him a chance, and Michele's warmth, Bacon said, "So I'm just sending love to everybody that knew him because I know everyone's hurting today. Today is a sad one. Thank you for everything, Rob. May you and Michele rest in peace."

Bacon and Cruise's co-star Demi Moore also shared her grief about the A Few Good Men director's passing, saying, "They were amazing people and wonderful parents who gave of themselves to make the world a better place. My heart, thoughts, and prayers are with their family, friends, and all that are affected by this tragedy."

Fellow Hollywood director Ron Howard also paid tribute, calling Reiner a "superlative filmmaker" and a "dedicated citizen", while Sir Elton John described Rob and Michele as "two of the most beautiful people" he'd ever met.

Others from the industry who paid tribute to the slain Hollywood duo included Monty Python star Eric Idle, actor John Cusack, and Elijah Wood of The Lord of The Rings fame.

Several Democrats, including former US Presidents Barack Obama and Bill Clinton, as well as former Vice President Kamala Harris shared their grief and disbelief at the news.