Replying to If you beat the crap out of someone outside of school...

So I need to beat the shit out of this one kid at my school for my own reasons. I actually think it'll so everyone some good if I do. Anyways, this is the first time in my life I actually like my school and I wanna stay in it. So I thought of the obvious and beat the shit out of him in school. Take him out back to the pizza place or something. But seeing as he is a student there and so am I and of course when someone asks him WTF happened to your face and  why the hell your rib cage is broken he's not gonna come up with some bullshit to protect me. So what im asking here is that if I beat the shit out of him can the school get involved despite the fact that I didnt do it on their time nor their grounds. And may I add in that this is a private school