The University of San Diego is a private university and is considered private property. The USD Department of Public Safety is charged with the primary responsibility of maintaining a safe campus environment. The authority to enforce University of San Diego policy is established by the Board of Trustees. A written agreement is also granted to USD Public Safety by the San Diego Police Department (SDPD) through a Memorandum of Understanding that permits USD Public Safety to investigate misdemeanor crimes occurring on USD property. However, the San Diego Police Department is the primary reporting and investigating agency for any violent crime that might occur on USD property.

Any person not a member of the USD community loitering on campus, attending a University-sponsored event for community members only or trespassing on University property will be asked to leave. At times when University-sponsored events are open to the public, the privilege of attending an activity and being on University property may be revoked at any time by a University official. Guests of USD community members who violate University rules or violate reasonable behavior considerations will be required to leave. Refusal to leave the campus after being asked to do so may subject the person to arrest per Section 602 of the California Penal Code (Trespassing).

The University of San Diego addresses the need to operate all motor vehicles safely on its campus through the parking policy. The USD parking policy recognizes that USD is not a public thoroughfare and USD roadways are considered private property. As a condition to granting permission to operate a motor vehicle on USD property, USD parking policy requires all vehicles operating on the USD campus comply with all posted traffic regulatory signs, the provisions of the California Vehicle Code, San Diego Municipal Code and University regulations. Vehicle operators in violation of the above codes or regulations are subject to traffic enforcement action by USD Public Safety Officers.