Easier to look the other way. They still get the same pay.
If the police are sworn officers of the State of Commufornia, they cannot look the other way without being subject to legal action. The injured party can sue the State for equal protection, etc.
If they're just campus rent-a-cops, the injured party can sue the University for failing to provide protection, too. But ideally, the State or the city or whatever legal subdivision is responsible for providing police protection on the campus should be forced by legal action to arrest and prosecute the perpetrators.
Then, once an arrest record has been established, if the particular Pile-of-slimian is not an American citizen, INS should be notified so they can start deportation proceedings. Believe me, FBI and INS and homeland security are only too happy to find any excuse to throw another screaming islamic monkey out of the country.