Students that physically assault other students at school should be dealt with by law enforcement and not teachers.

The title really.

Having their kids reported to police if they're being little shits at school may encourage parents to discipline their children more effectively. Being cuffed and taken to a police station may also give them a wake up call.

Secondly, teachers are employed to teach, not wrestle and restrain rowdy kids.

Edit: For some clarification on my stance regarding age. I believe that if it gets to the point where young kids have physically assaulted and injured another student, the parents have clearly failed in their duty. In this situation, I'm not recommending prosecution, but I am recommending law enforcement be contacted, if only to put some fear into the kid by taking them to the station and explaining that their actions have consequences. The parents should also be questioned thoroughly here, to look for any potential abuse at home.

In the case of young teens and onwards, I'm leaning towards having a harsher response. By the time you're at that age, you should already have a very good grasp of right and wrong. It's not down to teachers to drill that into you. Although, I'm also open to the approach of having a one strike policy, i.e. if you start a fight for the first time, you don't get treated like a full on criminal, but instead get lectured about your actions and their consequences. If you're a repeat offender however, I vote that you face more serious repercussions.