Attorney Alan Jackson Says Nick Is NOT Guilty of Murder After Withdrawing From Case

10:43 AM PT -- Los Angeles County District Attorney Nathan Hochman says prosecutors are confident a jury will find Nick Reiner guilty of murdering his parents, no matter who he has as a defense lawyer.

10:32 AM PT -- Alan Jackson just held a brief news conference where he said there's one thing everyone can take to the bank -- "Nick Reiner is NOT guilty of murder."

Jackson said the circumstances under which he had to withdraw from the case were beyond Nick's control. TMZ broke the story ... Nick was diagnosed with schizo-affective disorder and there are issues regarding his meds that could lead to a plea of not guilty by reason of insanity.

10:06 AM PT -- A spokesperson for the Reiner family released a statement on Nick's change of legal representation saying ... "They have the utmost trust in the legal process and will not comment further on matters related to the legal proceedings."

A source told The New York Times the change had nothing to do with Alan's "performance" and that he had been a pro.

9:52 AM PT -- Nick Reiner's new attorney is public defender Kimberly Greene, who has 19 years' experience.

The judge signed off on Nick's change of legal representation and set a new arraignment date for Feb. 23. Nick spoke up in court, saying, "Uh, yeah I agree with that."

Nick's leaving the courtroom and going back to jail -- he still has no bail -- and Alan is about to address the media ... tune into the live stream above.

Nick Reiner's lawyer is off the case, TMZ has learned, and Nick will -- at least for the time being -- be represented by a public defender.

Sources connected to the Reiner family, with direct knowledge, tell TMZ ... when attorney Alan Jackson appears in court Wednesday morning for Nick's arraignment, he will inform the judge he is no longer representing Nick.

Our sources say a public defender will step in for now, and the case will be continued. Nick will not enter a plea.

As for why Jackson is off the case, we're told the family will be releasing a statement as soon as the proceedings are over, and TMZ will post it.

TMZ reported, it's likely Nick will eventually plead not guilty by reason of insanity. He was diagnosed with a form of schizophrenia -- schizoaffective disorder -- and we're told his meds had sent him off the rails in the month before the murders.

Jackson is coming off a huge victory in the Karen Read trial in Boston, where she was found not guilty for allegedly killing her boyfriend.

It's unclear if the public defender is a stopgap until another lawyer takes the case, or if the public defender will handle the case from this point forward.