@zemichi @matrix 'use it' could mean 'use it to intimidate would be looters to stay away from this business'. If they want to convict him on 1st degree murder, they'd have to prove beyond a reasonable doubt that at least at some point during that night, he was trying to antagonize people into a situation where he could shoot them and claim self defense. Unless there's some unreleased video of him getting in people's faces he's going to walk. Keep in mind that having a gun, even illegally, does not remove his self defense privilege.
See:
https://docs.legis.wisconsin.gov/statutes/statutes/939/III/48Kyle had privilege of self protection under 939.48(2)(b), and the group of assailants lost theirs under 939.48(2)(c)
He may want to explore life in south america or the motherland