No. It is a criminal matter and should be reported to the police.
Only if the car was actually stolen. Nonpayment isn't theft (a criminal matter), it's a civil matter.
If you just bought it and ask the police to check it and then it turns out to be stolen, in all likelihood you'd be in no trouble at all; you're just trying to verify the gun is clean. If it does turn out to be stolen, however, the police have to confiscate the gun, so you'd be out whatever you paid for it unless you filed a civil suit against the seller.
US Civil war
what gun are we talking about here
No, its a Civil matter. Law Enforcement deals in Criminal Law, not Civil Law.
The police will not take a stolen vehicle report if the automobile's owner handed the keys to the individual. It is a civil matter in this instance.
Contact your local police department and give them the serial number. The Police can check on the stolen gun list maintained by the BATFE. If the gun is stolen, the Police will conficate the piece and begin investigation of how it was acquired.
Contact the police.
Expect the police to expect YOU to explain how you came to possess a gun that had been stolen- just like any other property.
Depends on the DA.
A Stolen gun
Take it to your local police