The pawn shop here notes down the serial numbers of the items you're pawning and enters them into a database before accepting the item for pawn.
If the item turns up stolen as listed in the database then the pawn shop will notify the police.
That's at least what happens at my local pawn shop. If the item doesn't have serial numbers or you can't prove ownership of the item you're pawning then they won't accept the item as pawn.
Still it could even later be shown as stolen in which case the pawn shop will notify the police and hand them over ID and info on the person who pawned the item to them.