Techniques for cable-free indoor gunshot detection are disclosed. Acoustic information is collected within an indoor environment using a gunshot sensor device which uses cable-free communication to a network. The gunshot sensor device is powered by a battery. Infrared information from the muzzle flash of a firearm is collected using the gunshot sensor device. The infrared information is buffered within the gunshot sensor device. The gunshot sensor device is used to monitor the acoustic information and identify a high-intensity gunshot sound. The gunshot sensor device is used to match the high-intensity gunshot sound to the buffered infrared information. The matching includes making a correspondence between the gunshot sound and an infrared event that occurred in time before the gunshot sound. The gunshot sensor device is used to notify the network of a possible gunshot occurrence, based on an analysis of the high-intensity gunshot sound and the infrared event that was matched.