A system includes a plurality of sensors distributed about a space. Each sensor generates sensor data associated with properties of one or more people in the space. An automated response subsystem receives the sensor data. An unauthorized activity performed by a first person in the space is detected based on at least a portion of the received sensor data. In response to detecting the unauthorized activity, tracking instructions are transmitted that identify the first person associated with the unauthorized activity. A tracking device receives the tracking instructions. A device associated with the first person is detected. Over a period of time, the tracking device sends queries to the device and receives corresponding responses from the device. The tracking device determines positions of the device within the space over the period of time.