Not even close.
Shooting somebody at random is a crime, whether it's your gun or someone else gun. The ownership of the gun has nothing to do with whether it's a crime or not. The one who pulled the trigger is committing a crime even if he has a license to the gun.
Selling a phone you own is not a crime(unlike shooting someone with a gun you own). Selling a phone you found after some guy had left it behind, when your attempts to return the phone to the presumed owner, have been repeatedly rejected by the presumed owner, who continued to insist he never lost any phone in the first place, is a totally different matter.
You really crack me up. You first of all compare some phone to America's nuclear secrets, then you graduate on to comparing this me-too phone to America's Abrams tanks, now you say its like someone shooting someone else in the head?
Say, do you have violent dreams when you go to bed at night?
1. property law,Have I missed any?
2. tort law, and
3. simple analogies.