Legal Question in Criminal Law in California

There is no way you can appeal the conviction, but your son may be able to. Pleading guilty severely restricts his appellate rights, as does the agreement that he signed. If he wants to back out of the deal, he should consult with an attorney right away and review the details of his case. If he was not properly informed of the rights he was giving up, he may be able to withdraw the plea and/or appeal it on that basis. But if he was so informed and has simply changed his mind, there is probably nothing he can do.

Appeals are subject to strict time limitations. I have no idea whether there is still time to file a notice of appeal in your son's case, or whether one has already been filed.

YOU can't appeal, you weren't the one convicted. You can certainly pay for an attorney to represent him. BUT, you already confirmed he waived his appeal rights in order to get the deal. There may be a couple grounds for appeal of all that, assuming he can somehow show legal 'incompetence' of both he and his attorney at the time in agreeing to the deal. Tough to win, and appeals are expensive. If you are serious about hiring counsel to try, feel free to contact me.