Here is how I see it. Call the police and ask if its stolen. Provide them with the serial number and have them run it to see if its registered to anyone. If its not registered or been reported stolen then post some flyers around the neighborhood. I'm not talkin about a 10 mile radius but within a few blocks. If no contacts you within a month keep the bike. If you just hand it over to the police it will end up at an auction and from what I have seen at the police auctions the kids bikes only sell for like 10-50 dollars. I don't see how its any better to just give it to the police if its not stolen or registered to an owner when all they are gonna do is sell it.