There is a growing pile of evidence that cities should drop Shotspotter, the notorious surveillance system that purportedly uses acoustic sensors to detect gunshots, due to its inaccuracies and the danger it creates in communities where it’s installed. In yet another blow to the product and the surveillance company behind it—SoundThinking—Congress members have sent a letter calling on the Department of Homeland Security to investigate how it provides funding to local police to deploy the product.

The seven page letter, from Senators Ed Markey, Ron Wyden and Elizabeth Warren, and Representative Ayanna Pressley, begins by questioning the “accuracy and effectiveness” of ShotSpotter, and then outlines some of the latest evidence of its abysmal performance, including multiple studies showing false positive rates—i.e. incorrectly classifying non-gunshot sounds as gunshots—at 70% or higher. In addition to its ineffectiveness, the Congress members voiced their serious concerns regarding ShotSpotter’s contribution to discrimination, civil rights violations, and poor policing practices due to the installation of most ShotSpotter sensors in overwhelmingly “Black, Brown and Latin[e] communities” at the request of local law enforcement. Together, the inefficacy of the technology and the placements can result in the deployment of police to what they expect to be a dangerous situation with guns drawn, increasing the chances of all-too-common police violence against civilians in the area.

In light of the grave concerns raised by the use of ShotSpotter, the lawmakers are demanding that DHS investigate its funding, and whether it’s an appropriate use of taxpayer dollars. We agree: DHS should investigate, and should end its program of offering grants to local law enforcement agencies to contract with SoundThinking. 

The letter can be read in its entirety here.