Legal Question in Criminal Law in California

Depends on the terms of his probation. If it is a term of probation that he not own or possess firearms, he would face substantial state prison time if caught with a so-called "assault weapon," even if it was legally registered prior to 1990. I don't know whether, after the probation is over, any intervening firearms prohibition interrupts or renders invalid the lawfulness of the former probationer's registered assault weapons possession. If it is really a "banned" weapon, which includes all automatic weapons and all unregistered semi-automatic "assault weapons," then he faces substantial prison time regardless of his probation status.

Having an illegal assault weapon is itself a crime, and committing a crime is a violation of your probation. Remember when the judge put you on probation, and said, "obey ALL laws?" That is what he was referring to. When you are on probation, and the court finds out about it, they set a probation revocation hearing. That means the court can impose the sentence it previously suspended for violating the probation. Then you can get an additional sentence for the new violation, possession of the illegal assault weapon. Get yourself a lawyer.

Federal and state prison or jail time, on multiple counts. First, for illegal weapon, then for violation of probation if you had a gun ban as part of the terms of probation. If that's you, either way you've got a serious problem. If serious about hiring counsel to defend you, feel free to contact me.