Municipalities and universities continue to negotiate police jurisdiction on and near campuses. Today, many universities and colleges maintain their own police forces. In cities where a significant number of students live off campus, university police may be allowed to patrol these neighbourhoods to provide an extra measure of security. Meanwhile, civil libertarians argue that school officials should only call on local law enforcement to intervene when it is necessary to protect the safety of people on campus. Such intrusion is legally mandated in some jurisdictions when school officials have reasonable suspicion to believe that a student is breaking the law. Generally, local police are reluctant to go on campus if a college maintains its own security force (the Kent State and Jackson State killings are examples of intervention turning into tragedy).