Was the gun in the shooting a ghost gun? Either way, ghost guns can be illegal independently of their connection to a shooting, so he's likely gonna get it for that if nothing else. But yeah, if it is the same gun, definitely should have destroyed that bad boy immediately.
The pictures they released previously had 2 to 3 different jackets, and 2 different backpacks, yet somehow he ditched all of that and not the incriminating stuff? Seems strange