LOS ANGELES — Nick Reiner displayed disruptive behavior at a holiday party attended with his parents, Rob Reiner and Michele Singer Reiner, just hours before the couple were found dead in their Los Angeles home, according to two people familiar with the situation.

Nick Reiner, 32 — who was arrested Sunday and later booked on suspicion of murder — reportedly made several guests uncomfortable during the gathering, which was hosted by comedian Conan O’Brien, one of the sources said. Another person said Rob and Michele Reiner appeared visibly upset and embarrassed by their son’s conduct and voiced concerns about his well-being.

Both sources spoke on the condition of anonymity due to the sensitivity of the matter.

The deaths of Rob Reiner, the acclaimed actor and filmmaker, and his wife have sent shockwaves through Hollywood, where the family was widely admired. At the same time, those close to the family were aware of longstanding struggles involving their younger son, particularly his battle with drug addiction. According to one source, Nick Reiner had been living intermittently at the family’s Brentwood home.

A representative for O’Brien did not immediately respond to a request for comment, and it was unclear whether Nick Reiner has retained legal counsel.

All three members of the Reiner family attended the holiday party together. One source described at least one interaction involving Nick Reiner that raised concern among guests. He is alleged to have interrupted a private conversation involving comedian Bill Hader. When Hader indicated the discussion was not open, Nick Reiner reportedly stood silently for a moment before abruptly walking away.

A representative for Hader also did not immediately respond to a request for comment.

Authorities have said the investigation into the deaths remains ongoing and that Nick Reiner is being held without bail.

One of four siblings, Nick Reiner has previously spoken publicly about his struggles with addiction and multiple stints in rehabilitation, which began when he was a teenager.

In 2015, Rob Reiner directed the film Being Charlie, which was co-written by Nick Reiner and drew heavily from his personal experiences. The film follows the story of a young man battling addiction while navigating the challenges of recovery.

Reflecting on the project during a 2016 appearance on NBC’s TODAY, Rob Reiner said the filmmaking process deepened his understanding of his son’s struggles. “What I didn’t understand was the depth of what he was going through,” he said. “Making the film forced me to see his experience — and forced him to see what his mother and I went through as well.”