A system and method for finding the proximate location of an indoor active shooter including: a plurality of acoustic sensors for receiving acoustic information from a monitored area, the sensors being dispersed in the monitored area, and each sensor having a processor for discriminating gunshot candidates from other sounds; and a host processor/server for receiving the gunshot candidates from the sensor and provide further processing to determine if the gunshot candidate is a gunshot. The server may use the first sensor to report as the proximate location of the shooter. As nearby sensors report the same incident, the server may refine the proximate location to within a few feet of the actual location of the shooter. The host processor includes a program or instructions to determine exit routes from the detected shooter and to activate a warning system which directs people away. The warning system includes a plurality of signaling lights capable of producing light in a plurality of selectable colors such that the host processor commands the lights to signal colors which warn people of the direction of the proximate location and other colors which direct people away from the proximate location.