I hope, for your son's sake, the guilty POS realizes the crime he committed is worse than your son doing the right thing and telling the authorities. Retaliation would be a fear even though your son did nothing wrong, aside from showing the gun while you were gone. And I hope the guilty POS's parents do not try to make their son the victim. I can hear it now "but he was just jealous that your son has nice things and he doesn't. He just thought that since your son has so much that it isn't fair and he wanted some of it too. It's not his fault."
The entitlement of the lazy and victim-role-play of the guilty in 'Merica today is sickening.
Anyways hope it works out and all parties involved become better from it.