Gunshot detection systems consist of microphones or acoustic sensors placed across a landscape to pick up loud noises which are then sent back to a base station for analysis and assessment, and to determine similarity to gunshots.
Police may assume these are gunshots, and report or respond to them as gunshots. Police keep data on the number of “shots detected” in an area, as determined by the system, and may use the information to justify ongoing or additional policing and surveillance.
Gunshot detection systems are also integrated in some cities with other tentacles of police surveillance (including Predictive Policing, Closed-circuit television (CCTV) cameras, ‣s, and Automatic License Plate Readers (ALPRs) through Real Time Crime Center (RTCC)).
This graphic detailing how ShotSpotter works is from a Region News Source 2023 article about Hammond, Indiana PD winning a DOJ grant for use of ShotSpotter.
Image description: A ShotSpotter gunshot detection system in Chicago, high up on a pole. Image source: cnn.com
ShotSpotter’s Impact on New York City’s BIPOC Communities. Image from ShotSpotter and the Misfires of Gun Detection Technology report.