A sentry robot system and method for operating the system is provided. In one embodiment, the robot system includes at least one functional robot with one or more environmental sensors and at least one navigator/controller platform. In another embodiment, the robot system includes one or more functional robots, one or more environmental sensors associated with at least one of the functional robots, and one or more navigator/controller platforms. The navigator/controller platform in this embodiment includes a receiver, a controller, a memory, and a transmitter. In one embodiment, the method includes creating an image map of the environment from environment data, periodically moving the functional robot to predetermined locations, collecting new environment data using the optical image sensor at each predetermined location, and comparing the new environment data to corresponding locations in the image map, and periodically determining if intervention is required due to changed conditions within the environment.