Nick Reiner Pleads Not Guilty on Charges of Murdering Parents Rob & Michele Singer Reiner

Nick Reiner appeared in a Los Angeles Superior Courtroom on Monday, where he was arraigned on two counts of first-degree murder.

At the hearing, Reiner entered a not guilty plea.

Cameras in the courtroom were able to capture Reiner, who was seen publicly in custody for the first time since the murders. His head was shaved and he wore a brown, prison-issued jumpsuit.

A reporter for "Extra" saw Reiner smirk when he walked in the courtroom.

Reiner was represented by public defender Kimberly Greene after his high-profile attorney Alan Jackson quit the case in January.

Last month, the prosecution added a special allegation that a knife was used in the killings with the two murder charges.

If Nick is convicted, he faces a maximum sentence of life without the possibility of parole or the death penalty.

Reiner was arrested after his parents were found dead in their Los Angeles home on December 14.

According to the Medical Examiner’s office, Rob and Michele died from “multiple sharp force injuries.” The manner of death for both was listed as “homicide.”

It was previously reported that Rob, Michele and Nick attended Conan O’Brien’s Christmas party the night before the couple was murdered.

O'Brien has broken his silence on the tragedy in an interview with The New Yorker.

Conan said, “I knew Rob and Michele, and then increasingly got closer and closer to them, and I was seeing them a lot. My wife and I were seeing them a lot, and they were so — they were just such lovely people. And to have that experience of saying goodnight 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.”

Family sources recently told TMZ that Rob and Nick got into a “very loud argument” at the holiday bash.

Afterward, Rob and Michele left the party. It was unknown if Nick left with them.

Rob and Michele’s daughter Romy found her father’s body the next day.

A person close to the family spoke to The New York Times, revealing the couple had a massage scheduled that day. When the massage therapist arrived at the gated home, no one answered.

The masseuse called Rob and Michele’s daughter Romy, who came over right away with a roommate.

Romy reportedly entered the house, but fled when she saw her father’s body.