Reiner is set to appear in a downtown Los Angeles courtroom on Monday for his arraignment on two counts of first-degree murder with his new lawyer Kimberly Greene, a public defender.
Reiner, 32, the third of Rob Reiner's four children, has been held without bail since his arrest hours after the actor-director and his wife of 36 years were found dead with stab wounds on December 14 at their home in the upscale Brentwood section of Los Angeles.
Reiner's previous lawyer, the high-profile private lawyer Alan Jackson, had to quit the case at the previous hearing in January because of what he called circumstances beyond his and his client's control.
He said legal ethics would not allow him to say why, but in parting he adamantly declared outside the courthouse that "pursuant to the laws of California, Nick Reiner is not guilty of murder".
Jackson did not elaborate but said the conclusion came after weeks of intensive investigation before his team had to hand the case off.
He said he wanted to push back against false reporting on the case.
It's not clear who hired Jackson to represent Reiner or who was paying the bill.
Generally, defendants use public defenders when they cannot afford a private lawyer.
Reiner is expected to plead not guilty, as is common for criminal defendants at this stage of the case, whatever their longer-term plan might be.
Reiner wore a suicide prevention smock at his initial court appearance in December but appeared without it at the hearing in January.
Rob Reiner, 78, and Michele Singer Reiner, 70, died from "multiple sharp force injuries", the LA County Medical Examiner said in initial findings. Authorities said they were killed hours before the bodies were discovered.
A court order has prevented the release of more details.
Authorities have said nothing about possible motives.
Prosecutors have said they have not yet decided whether to seek the death penalty for Nick Reiner, who is eligible for it under the charges.
Rob Reiner was a prolific director whose work included some of the most memorable and endlessly watchable movies of the 1980s and '90s.
His credits included This is Spinal Tap, Stand By Me, A Few Good Men, and When Harry Met Sally, during whose production he met photographer Michele Singer and married her soon after.
