The catch-all is "improper storage of a firearm" and he'll definitely get that one. I wouldn't doubt that the charges would stick. After all, these poor, dis-enfranchised fellows were simply engaging in an alternate lifestyle....bla, bla bla
This is typical.
If they left him alive, he was supposed to phone the police, who would probably not attend, but would tell him to simply let his home insurance deal with it.