ShotSpotter: Cities Waste Millions on Spotty Gunshot Detection Technology

Patrick K. Lin
4 min readOct 4, 2022


This article was originally published in my LinkedIn newsletter, Tech Support.

Cities across the United States are relying more and more on gunshot detection technology — a combination of microphones, audio analytics software, and human analysts — to identify sounds that may (or may not) be gunshots. The audio snippets that get picked up are automatically sent to analysts, who attempt to verify whether the sound is in fact a gunshot. The analysts then send information about the potential shooting, namely the location, to its clients: police departments.

ShotSpotter is the posterchild of gunshot detection technology. As of March 2022, the company reports that at least 130 U.S. cities and towns have installed its technology, up from 85 cities in 2018. Federal funding, particularly the American Rescue Plan Act (ARPA), facilitated ShotSpotter’s expansion. $10 billion of ARPA funds have already been allocated to law enforcement projects as of May 2022, largely due to spending requests from Democrats despite calls to defund police. It is worth noting that ARPA was intended to ease the economic hardship of the COVID-19 pandemic.

Although ShotSpotter has gained a foothold in many U.S. cities, the technology has not made much of an impact on gun violence and generally fails to result in investigatory leads, according to a new report from the Surveillance Technology Oversight Project (S.T.O.P.). Still, Chicago extended its $33 million contract by two years and New York City added three years and $22 million to its own contract with ShotSpotter. Together, Chicago and New York City account for nearly half of the company’s first quarter revenue this year, according to filings with the U.S. Securities and Exchange Commission (SEC).

All this government spending on snake-oil solutions brings a heightened police presence to historically overpoliced neighborhoods with little to show for it. In fact, evidence suggests that ShotSpotter wastes police officers’ time, causing unnecessary police stops. For example, when Chicago’s Office of Inspector General conducted an audit of ShotSpotter last year, it found that of the more than 50,000 alerts for probable gunshots, only 9.1 percent led to evidence of a gun-related criminal offense. The audit found that ShotSpotter alerts rarely produced evidence of a gun-related crime, an investigatory stop, or the recovery of a firearm. Instead, Chicago police were more likely to stop people based on the frequency of ShotSpotter alerts.

Police stops have been shown to have a negative impact on community trust. Similarly, the implementation of ShotSpotter has deteriorated helpful community involvement. In St. Louis, for example, citizen-initiated gunshot reports were over seven times more useful to police than ShotSpotter alerts, reducing the time officers took to investigate or patrol. However, citizen reports dropped when ShotSpotter was used and fell again when St. Louis expanded its ShotSpotter installation, suggesting that St. Louis traded in free, community-led assistance for an expensive, unreliable microphone.

This erosion of community trust emphasizes other issues with policing, particularly its discriminatory nature. Surveillance and racism have always been intertwined. According to S.T.O.P.’s report, in Chicago, Cleveland, Atlanta, and Kansas City, ShotSpotter devices are installed almost exclusively in Black and Latinx neighborhoods. In New York City, of the 31 New York Police Department (NYPD) precincts that deployed ShotSpotter, 70 percent were deployed in majority Black or majority Latinx precincts.

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As we have seen time and time again, these kinds of policing practices result in discriminatory and deadly encounters with police. Law enforcement’s history of over-policing poor communities and communities of color has in turn produced crime data that overrepresents these communities and their residents. Police departments use this skewed crime data to rationalize continued and increased over-policing of these communities, and the cycle feeds itself. ShotSpotter compounds this problem by using this very same police data to identify and justify the placement of its devices in purported “gun violent areas” of a city.

Law enforcement use of ShotSpotter also raises serious privacy concerns. If ShotSpotter is listening for gunshots, what stops it from listening to conversations? After all, ShotSpotter’s microphones record audio 24/7 and store recordings for 30 hours until they are overwritten on a rolling basis. The Legal Aid Society has called ShotSpotter’s product “a massive eavesdropping device” and expressed concerns about its misuse as a voice surveillance tool. In 2015, ShotSpotter’s own engineer testified in a Massachusetts criminal case that the device records anything it hears, including conversations conducted at normal volume up to 50 feet away.

Still, perhaps cities’ expensive and misplaced bet on surveillance technology like ShotSpotter is an indication that cities are attempting to address gun violence. A combination of increases in gun sales, economic distress, and social isolation due to the COVID-19 pandemic have inflamed the U.S. gun violence crisis. However, tech solutionism cannot be a replacement for real policy changes to address systemic inequities, such as gun control, affordable housing, affordable health care, and funding for public education.



Patrick K. Lin

Patrick K. Lin is a New York City-based author focused on researching technology law and policy, artificial intelligence, surveillance, and data privacy.