You know what? What planet are you from? This transaction took place across state lines and that makes it technically a federal crime because of interstate commerce. And if they mailed it, there is another federal crime. That is plain and simple. But with that said, unless the amount is large, the feds will usually steer you to the state and local authoritiies.
This is CABL.com posting #288292. Tiny Link: cabl.co/mbm92