Acoustic gun detection systems (AGDS) are a law enforcement technology designed to detect gunshot sounds and notify police of the event and location in close to real time. ShotSpotter is the most well-known AGDS in the United States, sold by a company of the same name. In what follows, we analyze ShotSpotter and the company’s claims that the system improves safety, reduces crime, and promotes positive relationships between communities and police. We conclude that the technology’s accuracy, effectiveness, cost, and systemic biases raise serious concerns. Communities concerned with local law enforcement’s purchase and deployment of AGDS can advocate for a variety of policy responses including: a ban, moratorium, community oversight, or technology assessment & deliberative democracy.