Follow up on the "finder": now it's in the system as stolen. Did she steal it? (It's stolen, but she didn't actually "steal it", did she?). If she knows she is not allowed to posses a firearm (underage, convicted felon or other reason) then I'm guessing she could face charges just for having it. What if she is legally able to possess a firearm? I think most of us would call law enforcement and turn it in (whether it was a gun, a wallet or "whatever") but I don't believe keeping something you found is illegal (firearms implications aside), is it?