A plea of “not guilty” is common at this stage, regardless of what the defence later does.
Reiner, who remains in jail and has not been granted bail, was ordered to return to court on April 29.
An arraignment would usually take place much sooner, but Reiner was unable to appear at the first scheduled attempt.
Another hearing last month was halted after the court heard that lawyer Alan Jackson was no longer representing Reiner.
The judge appointed an attorney from the public defender’s office in his stead.
Jackson, a high-profile attorney who has previously represented Hollywood clients including Harvey Weinstein and Kevin Spacey, told reporters he was “legally and ethically” barred from explaining why he had stepped back.
“Circumstances beyond our control, but more importantly, circumstances beyond Nick’s control have dictated that, sadly, it’s made it impossible for us to continue our representation of Nick,” he said.
Jackson said he and his team remained committed to Reiner’s best interests and had faith that the legal process would “reveal the true facts of the circumstances surrounding this case”.
“We’ve investigated this matter top to bottom, back to front. What we’ve learned – and you can take this to the bank – is that pursuant to the laws of this state, pursuant to the law in California, Nick Reiner is not guilty of murder.”
If convicted as charged, Reiner could face life in prison without parole, or the death penalty, although California does not routinely carry out capital punishment.
Los Angeles County District Attorney Nathan Hochman told reporters outside court his office would be examining the circumstances around the killings before making a decision on whether to ask for the death penalty if Reiner is convicted.
Erratic behaviour
Reiner, who lived in a guest house on his parents’ property, had attended a party at the home of comedian Conan O’Brien on December 13 with his parents, where some guests reportedly spoke of his behaving erratically.
The New York Times, citing a source close to the family, said the couple had been due to dine with former President Barack Obama and his wife Michelle on Sunday evening, and had seemingly booked an in-home massage for that day.
The paper said that when no one answered the door for the appointment, the therapist contacted the couple’s daughter, Romy Reiner.
When she arrived with a friend, she discovered her father’s body, and emergency services were called. Paramedics told her that her mother’s body was also at the property.
Police arrested Nick Reiner several kilometres away from the scene of the crime later that night.
Rob Reiner, the son of legendary comedian Carl Reiner, started his showbiz career in acting.
He won fame as the oafish son-in-law Michael “Meathead” Stivic on groundbreaking 1970s sitcom All in the Family, before transitioning to directing.
As a director, he struck Hollywood gold.
His output included 1984’s rock music mockumentary This is Spinal Tap, fantasy gem The Princess Bride from 1987, and seminal coming-of-age movie Stand By Me.
A Few Good Men, starring Hollywood heavyweights Tom Cruise and Jack Nicholson, earned an Oscar nomination for Best Picture.
– Agence France-Presse