Monitoring system and method for identifying object of interest after the object of interest has undergone a change in appearance. The method includes detecting an appearance of a first object of interest in a first zone and determining whether the first object of interest has appeared in a second zone adjacent the first zone within a predetermined time. When the first object of interest has not appeared in the second zone within the predetermined time, the method includes adding the first object of interest to a disappearance database and detecting an unexplained appearance of a second object of interest in a third zone of the plurality of zones. When an unexplained appearance of the second object of interest is detected, the method includes adding the second object of interest to a suspect database, and generating a notification for a first responder regarding the second object of interest.