Consult with a criminal defense attorney. Remember, though, that lawyers are not created equal, and not all lawyers have the necessary experience in the criminal justice field, and the local knowledge (e.g. San Diego County Courts) to be of real assistance. You wouldn’t go to a foot doctor for a heart problem.
A lot of people think: “I know I didn’t do anything wrong, so I have nothing to worry about.” Unfortunately, our system is not that perfect. If you aren’t convinced, look up the various Innocence Projects throughout the country that have exonerated wrongfully convicted people. People who were innocent, spoke to police to tell their truth, and were still arrested, charged, prosecuted, convicted, and sent to prison.