Maybe I mis-read the article, I am at work and do get interupted by phone calls from my sales department constantly.
He had the vest on at school, but the guns were at home.
Last time I checked, it was completely legal to have a AK and a shotgun and the ammunition for those at your house. It is also legal to purchase 'long guns' (shotguns/rifles) and ammunition as long as you are 18+.
There has to be more to the story, the charges were Armed Tresspassing, he was a student at the school so that's not a tresspassing charge. Grand theft, nothign in the article mentioned him stealing anything. And Criminal Mischief, my firend got charged with that for shooting people on the sidewalk with a water gun from a hotel balcony... kinda like disorderly conduct, it's the catch all law to arrest you for being annoying.