Rob and Michele Reiner reportedly received warnings from medical staff about their son Nick's behavior in the weeks leading up to their fatal stabbing.

Source say that Nick, 32, had recently fired his psychiatrist and changed his medication, saying the prescriptions "weren't working anymore" for him.

Medical professionals allegedly cautioned the couple against allowing Nick to live in close proximity to them during the transition. "They could exhibit even more erratic behavior as his body adjusted to the change," the source explained to US Weekly.

A second insider confirmed, "Medical staff warned Rob and Michele not to let Nick live at home until he got his medication straightened out."

Despite the warnings, Nick was reportedly living in a guesthouse on the Reiner's Brentwood property at the time of their deaths.

Rob, 78, and Michele, 70, were found dead in their home on December 14, 2025, hours after attending a Christmas party. The couple's cause of death was ruled "multiple sharp force injuries."

Nick Reiner was later arrested and charged with their murders. He appeared in court on February 23 and pleaded not guilty to two counts of first-degree murder.

Los Angeles County District Attorney Nathan Hochman said Nick could be "eligible" for the death penalty if convicted. He added, "When we get all this information, it will be subject to not only a rigorous analysis, but many of the most experienced individuals in the DA office with death penalty experience will be helping me evaluate that information."

Rob and Michele's other children, Jake, 34, and Romy, 27, confirmed their parents' deaths in a statement on December 17, 2025.

"Words cannot even begin to describe the unimaginable pain we are experiencing every moment of the day," they said. "They weren't just our parents; they were our best friends."

A source later told Radar Online that the family has not been in contact with Nick since the murders. "They just cannot handle that at the moment," the insider said.

Hollywood mourned the Reiners deaths, with Conan O'Brien describing himself as "in shock," and Chris Sarandon saying Reiner "changed" his life. Billy Crystal, Martin Short, Larry David, and Albert Brooks released a joint statement praising the filmmaker.

"Rob was also a passionate, brave citizen, who not only cared for this country he loved, he did everything he could to make it better, and with his loving wife Michele, he had the perfect partner," they wrote. "They were a special force together—dynamic, unselfish and inspiring. We were their friends, and we will miss them forever."