Gee, they left in such a hurry. Could it have been the owner's gun? But the jewelry store owner should have never gone near the guy with the hammer. The only thing that belonged near the hammer guy was a copper-jacketed hollow point. Or two. Or three.
The best thing to remember is...."When Danger is only Seconds away, the Police are only Minutes away". About all the police can do is count the bodies AFTER the violence.