Police are responding to a specific threat against students at the University of Bridgeport.An anonymous letter sent to police headquarters Tuesday mentioned some students' first names and one of the residence halls as part of the threat. Once they contacted the university, the officers were brought on campus. Now, police are patrolling the university's four main residence halls around the clock. Many students say they were not aware of the threat. Police don't typically patrol the dorms, but some students say it's a good idea considering the threat.