Have someone - even yourself - approach the ratbastard. Tell Lil' Al Capone that the cops got his identity and fingerprints (LIE!) and to just give you back the bike. Do this - you won't file charges. If he won't: Tell him you have friends that work in jail. And you'll tell them to spread the rumor that he's in jail for diddling kids.

Cruel. But extremely effective.