Legal Question in Criminal Law in California

Nothing. Records are forever. That is the whole purpose of the justice system keeping them, to keep track of 'priors', arrests, trials and convictions. Errors can be corrected, but accurate info stays there forever.

I agree with Mr. Nelson, and I want to add two points.

First, arrest records are not publicly available. The FBI and other law enforcement agencies can see them, but the general public can't.

Second, your record says only that you were arrested, not that you were convicted. An arrest means only that someone made a credible accusation against you, not that you were guilty. That's an important distinction which law enforcement agencies understand. Many in the general public don't, which is one reason why the public doesn't have access to these records.