Principals, Teachers, now Cops (New Hampshire)

So a high school student swipes his sister's purse and won't give it back. Teachers and the principal escalate the situation and before too long the student ends up suspended. For reasons I don't begin to understand,  a detective is on the scene. The kid asks "what the fuck" he got arrested for and apparently that's too much for our high-strung flatfoot. Aren't you glad the police got involved in this one?