California's code of Civil Procedure provides in section 340 that there is a one year statute of limitations for "[a]n action upon a statute for a penalty or forfeiture, if the action is given to an individual, or to an individual and the state, except if the statute imposing it prescribes a different limitation." California Penal Code section 632 does not separately provide for a different statute of limitations. Case law has held that the statute does not start to run until discovery of the secret recording. Therefore you needed to file an action against the offender within one year or learning of the offensive recording.
Sorry, it appears your action is time-barred. Good luck to you.
This answer should not be construed to create any attorney-client relationship. Such a relationship can be formed only through the mutual execution of an attorney-client agreement. The answer given is based on the extremely limited facts provided and the proper course of action might change significantly with the introduction of other facts. All who read this answer should not rely on the answer to govern their conduct. Please seek the advice of competent counsel after disclosing all facts to that attorney. This answer is intended for California residents only. The answering party is only licensed to practice in the State of California.
In addition to Mr. Pedersen's answer, you cannot prosecute anyone for potential criminal acts. You can report the incident to the local police, and if they decide to, they will forward it to the DA for prosecution.