For pete's sake, guys. They both share some responsibility in this. The girl was obviously being disruptive and belligerent. She's not blameless. The cop obviously lost his temper and there's not really any excuse for his body slamming a teenage girl who wasn't physically threatening anyone. Teachers, administrators, and resource officers deal with belligerent kids in every school, everywhere, every day, for the most part without body slamming them. He's not blameless either. Ideally, both should face some form of repercussion.
Let's acknowledge this is an ugly incident, neither party is "in the right", and move on.
It's amazing how you guys are able to take any seemingly benign bit of news and make it into a knock-down, drag-out, left/right war. Actually, I take it back. It gives me something to read when I'm procrastinating, so please, continue.