Oh, I agree with you on the paper trail part. I just meant more from a forensics point of view. Any potential fingerprints (although suspect was likely wearing gloves), potential sweat or any other source of DNA. If there isn't any evidence on the gun or ammo itself its going to make it a lot harder to find the shooter. I would imagine they would have to look for cell phones in the area that left the area the fastest. Not really sure though.