LOS ANGELES (AP) — A Los Angeles County grand jury has indicted Nick Reiner on murder charges in the killings of his parents, actor Rob Reiner and Michele Singer Reiner, and adds the allegation that he was lying in wait before attacking them.

The grand jury, which had been meeting in secret, returned the indictment on July 20, and it was unsealed Wednesday, when Nick Reiner entered a not guilty plea.

The director, actor and Hollywood luminary Rob Reiner and his wife, photographer and producer Michele Singer Reiner, were stabbed to death in their home in the upscale Brentwood section of Los Angeles on Dec. 14. Nick Reiner was arrested hours later and charged two days later.

The grand jury indictment is a major step toward trial and allows prosecutors to skip California’s preliminary hearing process, where evidence is publicly aired.

The unsealed indictment reveals few new details in a case that has been shrouded in secrecy. But the lying in wait allegation along with other circumstances mean Reiner is elligible for the death penalty. Prosecutors say they haven’t decided whether to seek it.