Cities Are Spending Millions on Gunshot Detection Technology that Fails to Show Results

As cities across the country debate how to respond to gun violence, a new Reset Report released today by the Independent Institute finds that acoustic gunshot detection systems have failed to deliver clear public safety results, despite years of multimillion-dollar contracts and vendor claims that the technology helps police respond faster and solve more crimes.

The report, The Echoing Failure of Acoustic Gunshot Detectors, examines how ShotSpotter and similar acoustic gunshot detection systems, known as AGDs, have become a case study in a police-technology accountability gap: cities across the nation have adopted an expensive tool amid public pressure over gun violence without evidence that it reduces shootings, improves arrest outcomes, or delivers measurable public safety outcomes.

“Gunshot detection technology was sold to cities as a high-tech answer to gun violence, but the evidence does not support that promise,” said Jonathan Hofer, Independent Institute Research Fellow and author of the report. “These systems often send police on wild goose chases and diverting officers from other calls. After two decades of use, the evidence still does not show that this technology is making communities safer, helping police solve cases, or justifying the public dollars spent on it.”

The report argues that cities should redirect scarce public safety dollars toward strategies with stronger evidence of helping police investigate shootings, solve cases and reduce violence.

Among the report’s findings:

1. AGD has not been proven to reduce gun violence or improve arrest outcomes: One of the largest studies of the technology, which analyzed 68 large metropolitan counties from 1999 to 2016, found that ShotSpotter had “no significant impact on firearm-related homicides or arrest outcomes.”
2. The technology can create large amounts of police activity with few results: In Chicago, more than 40,000 unproductive deployments occurred in less than two years, consuming more than 20,000 patrol hours and diverting officers from genuine emergencies, according to the report. The report also notes that false-positive rates for AGD systems consistently exceed 80% in major cities.
3. Vendor accuracy claims do not answer the key public safety question: ShotSpotter has claimed a 97% accuracy rate, but the report argues that the more important question is whether an alert leads to evidence of gunfire, arrests, victim aid, or solved cases.

The report highlights a growing national backlash against acoustic gunshot detection systems:

1. San Antonio, TX, dropped AGD after spending $546,000, with police finding no evidence of a shooting 80% of the time and no observed reduction in gunfire where the system was used.
2. Troy, NY, ended its AGD contract after officials concluded the system could not reliably distinguish gunshots from other loud sounds, including truck brakes and firecrackers.
3. New Orleans, LA, dropped AGD maker SoundThinking after five years because officials could not show it had produced meaningful results, even as the city continued to have one of the nation’s highest murder rates.
4. Charlotte, NC, declined to renew its AGD contract after police found evidence of gunfire in only 1 out of 41 alerts reviewed by The Charlotte Observer.
5. Fall River, MA, ended its AGD program after the police chief said the system produced too many false alarms, missed real gunfire and worked less than half the time.
6. Atlanta, GA, declined to adopt AGD after two separate SoundThinking trials, suggesting the city was not convinced the technology justified implementation.
7. Dayton, OH, terminated its AGD contract after officials said it was difficult to show that ShotSpotter was effective on its own.
8. Portland, OR, walked away from AGD negotiations after concerns about vendor lobbying and a finding that the system’s benefits did not justify its cost.
9. San Diego, CA, reassessed AGD after records showed 584 alerts over four years but only one arrest clearly connected to a specific alert.
10. Chicago, IL, let its SoundThinking contract expire after years of criticism, with city leaders saying they wanted to shift resources toward more effective violence-reduction strategies.

The report recommends that cities instead invest in public safety strategies with stronger evidence of effectiveness, including adequate homicide detective staffing, modern case management systems, and intelligence-led policing.

For cities that continue using the technology, the report calls for public reporting on whether AGD alerts are accurate, whether they help police solve cases, how they affect response times, how much they cost legally, and whether the overall benefits justify the expense, including officer time and opportunity costs.

The Reset Report is the Independent Institute’s flagship policy series for readers who want to understand why something is not working and how it can be fixed. Each report examines a major government failure in depth: the decisions and entities that caused it, the cost to real people, and the path to a genuine fix. The series advances public conversation with rigorous analysis and practical recommendations for reform.

For more information, contact Robert Ade, [email protected], or (510) 632-1366 ext. 114.

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