Nick Reiner has pleaded not guilty in connection with the murder of his parents Rob and Michele Reiner.

Nick smirked at the audience as he walked into the courtroom. The 32-year-old was arrested December 15 and charged with first-degree murder the next day. The charges include a special circumstances allegation, which puts the death sentence on the table if prosecutors choose to pursue capital punishment.

As you know … Rob, 78, and his wife Michele, 68, were found stabbed to death inside their Brentwood home Sunday, December 14.

Nick was initially represented by powerhouse attorney Alan Jackson, but Jackson dropped out of the case at Nick’s January 7 arraignment, causing it to be delayed.

Alan said the circumstances under which he had to withdraw from the case were beyond Nick’s control, but later held a news conference proclaiming, “Nick Reiner is NOT guilty of murder.”

Subsequently, Kimberly Green — a deputy public defender with 19 years of experience — stepped in to fill Alan’s shoes. We got Kimberly as she was walking into the courtroom Monday.

When asked how Nick was feeling, she responded, “No comment.”

We were previously told Nick was diagnosed with schizoaffective disorder — and his meds had sent him off the rails in the month before the murders.