Nick Reiner’s weight gain fueled parents’ murders, doc claims

Nick Reiner’s weight gain and change of meds for his schizophrenia treatment was reportedly the catalyst behind his parents Rob Reiner and Michele Singer Reiner’s brutal murders.

Sources made the revelations surrounding Nick’s 2020 diagnosis and subsequent struggles with his medication regimen in TMZ’s new documentary, “The Reiner Murders: What Really Happened,” which aired on Friday.

In December, the outlet reported that Nick, 32, was diagnosed with schizophrenia — and in the weeks leading up to his parents’ deaths, the meds he was taking allegedly made him “erratic and dangerous.”

Multiple sources told the outlet that Nick was under the care of a psychiatrist for mental illness and that his behavior had gotten “alarming” in the month before the murders.

Nick reportedly received care from a Los Angeles-based rehab facility in the weeks leading up to his parents’ murders.

However, sources in the documentary told the outlet that Nick complained to his doctors about the weight gain he had experienced, which is a common side effect of the medication.

As a result of his complaint, his doctors changed his meds which led him to become “more erratic.”

Insiders added that Rob and Michele Reiner were aware of the troubling updates with their son, but were unsure of what to do.

Doctors also allegedly decided not to place Nick on a temporary psych hold to stabilize him during this time, the sources continued.

Nick’s attorney, public defender Kimberly Greene, did not immediately respond to Page Six’s request for comment.

Rob and Michele were found fatally stabbed to death in their Los Angeles home on Dec. 14, 2025, after having been involved in a heated argument with Nick the night before. Rob was 78 and Michele was 70.

The young filmmaker, who has had a notoriously rocky relationship with his parents and publicly struggled with drug addiction for years, was arrested hours after his parents’ bodies were discovered. He is currently facing two counts of first degree murder in the stabbing death of his parents.

After changing out his representation from famed attorney Alan Jackson to Greene, it was reported that Nick doesn’t understand why he’s in jail.

Sources claim Nick believes those who put him behind bars are engaged in a “conspiracy” against him. While he is aware of his alleged crime, the insiders added that he’s experiencing a break from reality.

In light of his representation updates, his arraignment date was pushed back once again during his Jan. 7 appearance in court.