Conan O'Brien speaks out for first time on Rob Reiner's death

Conan O’Brien has opened up about his good friends Rob and Michele Reiner after the couple were found dead in their Los Angeles home last December.

Their son Nick Reiner, 32, has been charged with two counts of first-degree murder, and attended O’Brien’s holiday party with his parents a day before they died.

“I knew Rob and Michele, and then increasingly got closer and closer to them,” the chat show host told The New Yorker.

“They were just such lovely people. And to have that experience of saying good night to somebody and having them leave and then find out the next day that they’re gone... I think I was in shock for quite a while afterward.

“I mean, there’s no other word for it. It’s just very—it’s so awful. It’s just so awful.

Conan was with the Reiners the night before they died (Michael Buckner/Variety via Getty Images)

“And I think about how Rob felt about things that are happening in the country, how involved he was, how much he put himself out there—and to have that voice go quiet in an instant is still hard for me to comprehend.”

Sources told People that Rob and Nick got into an argument at O'Brien's party.

"Nick was freaking everyone out, acting crazy, kept asking people if they were famous," a person who attended told the outlet.

The When Harry Met Sally... filmmaker's son - who was homeless at points - went to rehab with drug addiction at least 18 times before he turned 22.

During Rob and Nick's 2015 interview with Zeitchik for the Los Angeles Times, Rob said: "The program works for some people, but it can’t work for everybody.

Nick has been charged with two counts of first-degree murder (Michael Buckner/Getty Images for Teen Vogue)

"When Nick would tell us that it wasn’t working for him, we wouldn’t listen.

"We were desperate, and because the people had diplomas on their wall.

"We listened to them when we should have been listening to our son."

Nick awaits trial in confinement at the Twin Towers Correctional Facility in LA.

Following a court appearance, Nick issued a no plea and his high-profile defense attorney stepped away from his case last month.

Four police sources told People that he is alone in his cell and is fed three meals a day.

"The inmates [where he is located] have significant mental health illnesses and need to be kept alone and away from any other people or inmates," said a Los Angeles County sheriff source.

"He has about an hour to eat and then a deputy sheriff collects his tray inside his cell."