A Smart Campus is a protected area within Smart Cities (Cities 2.0) where physical security of assets is vital for the continuous operation of the university. Concretely, there are specific mission-critical areas on the campus, which should be protected from unauthorized and malicious individuals. This paper describes a sustainable Smart Campus system architecture based on individuals' spatiotemporal authentication fingerprint, generated by fusing data from mobile GPS devices and CCTV cameras infrastructure to detect malicious user behavior. The system incorporates unobtrusive monitoring to collect data from such individuals. While the system monitors for unauthorized access to restricted locations within the campus area, data are analyzed by an intrusion detection algorithm that sets off alarms and prompts physical evacuation. The efficiency of the proposed system is evaluated by gauging the prediction accuracy of alarms triggered and response time to the actual incidents on the campus. Results are promising for the adoption of the proposed system architecture by universities in Cities 2.0.