Legal Question in Criminal Law in California

Probably nothing effective. Scammers don't play nice or cooperate in you locating them. File a complaint with the post office if any of the transaction was done by mail. If eBay or PayPal was used, complain to them. Call your bank or credit card company to try to stop payment and report the fraud. If it was a real person, local to you, you could sue if you can find them. You can try to report a crime to your police.