Police shouldn't even go along with it and arrest the kid in the first place. Much less the school be such morons.
I can understand because I was handcuffed for being a "runaway" when my mom called the cops on me for being pissed and going into my room. (If anyone remembers that from a while back.)
People take things WAY over the line, regaurdless of what the kid's intentions were, you don't press charges against a student for technically not even doing anything (yet, atleast).