Because your were found not guilty of the charges, that alone does not support a cause of action against the government. Contact a CA lawyer right away. If the deadline has passed on false arrest, you may be told that all potential relief is now barred because of statute of limitations expiration.
Check with a lawyer in your locale to discuss more of the details.
Good luck to you.
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For your information, you have mistated the law. A finding of factual innocence does NOT prove that the police never had probable cause to arrest you. It is a common misconception among client, lawyers, prosecutors and even judges. It is quite possible for a cop to have probable cause to arrest you, and then later new evidence is discovered or produced in court about which the officer knew nothing, and then you are proved innocent. Hence, it can be a situation where both you and the arresting officer were right.
Example: a citizen standing on the sidewalk down the street from a bank identifies a man in green troussers as a bank robber, saying he saw him do it. The officer then has probable cause to arrest the man. However, it turns out that this was a SECOND man in green pants and the witness made a mistake. The arrested man was in fact being written up half a mile away by a cop for speeding at the time of the robbery. Result: the cop had probable cause to arrest him, but he was factually innocent.
In addition, the court order finding you factually innocent is NOT admissible in court in your contemplated law suit against the state. Check P.C. Sec. 851.8 itself, which says it is not.