Flock Safety, the main supplier of the recently controversial roadside cameras that scan passing cars, offers more than automated license plate readers (ALPRs). The company also sells a surveillance bundle of sorts called the "Safe City" subscription. Billed as Flock's "Most Complete Solution," the "Safe City" subscription includes the much-discussed ALPRs, along with a live video camera—and a gunfire microphone. Bundling these together risks turning lawful gun owners into criminal suspects based only on proximity.
It is hard to find reliable information about the number of active gunfire microphones in the United States. The Electronic Frontier Foundation's Atlas of Surveillance documents nearly 250 gunshot-detection deployments and purchase plans nationwide, although that includes programs that have since ended. Cities also have deployed firearm detection systems that rely on AI to detect visible firearms on video or combine acoustic and dual-sensor infrared cameras to detect gunshots.