"Resort to" seems like it's understating a bit the conscious choice of violence on the cops' part. These demonstrations have been putting nonviolent pressure on the university admins to divest, that's all. And the protesters are treated like an armed force who is inflicting violence. So far, as far as I know, the only ones starting violence have been israel supporting zionists who have shown up to UCLA (may have been other universities too, not sure) and based on reports and some clips I saw, attacked the encampment with fireworks, attacked people with baseball bats and wooden boards, assaulting them for hours, while security and cops either left or stood by and did nothing.