I've read several accounts now of students being involved. I've also heard of staff  members being involved.  I tend to believe those statements. There  were a large number of protesters on a college campus. It would be ignorant to think some if not the majority were not students. Here is an article from someone who was involved in the riot first hand and witnessed  students joining in, not all dressed in black garb. These people should be punished to the full extent of the law. You cannot condemn hate and violence with hate and violence. 
https://itsgoingdown.org/beating-milo-how-berkeley-defeated-alt-rights-biggest-troll/