Bang, Boom, Pop — Gunshot?

Does ShotSpotter make your community safer? No, not according to the research.

ShotSpotter, Inc. expands the footprint of police departments without making communities safer. ShotSpotter’s technology often mistakes loud noises for gunshots, leading to more police encounters with civilians, sometimes resulting in fatal outcomes.

Research in cities to date shows:

  • ShotSpotter increases dangerous encounters between police and innocent civilians
  • ShotSpotter has no significant impact on gun violence
  • ShotSpotter rarely finds actionable evidence of a gun crime
  • ShotSpotter wastes millions of taxpayer dollars
View All Claims

What is ShotSpotter?

ShotSpotter has been deployed to 100+ cities and counties.

ShotSpotter is paid by cities to set up microphones in secret locations throughout neighborhoods, using triangulation technology to locate loud, impulsive noises.

  • Step 1 A loud noise is detected by ShotSpotter sensors.
  • Step 2 Step 2 The recording is sent to a ShotSpotter technician, who often has no scientific background or expertise, who tries to determine whether the noise is a gunshot.
  • Step 3 If the technician judges the sound to be a gunshot, the general location of the sound is published to local dispatch and/or police officers in the coverage area.

ShotSpotter has never been independently validated/tested for its ability to accurately distinguish among various loud noises. Without scientific testing, we don’t know how many impulsive sounds are incorrectly classified as gunfire.

How ShotSpotter Works

Is ShotSpotter Near You?

There are active ShotSpotter contracts in over 100 cities. Find the one closest to you.

Search below to learn more.

ShotSpotter Contract Status



Rejected / Cancelled

Noise-Detection Quiz

Which sound could cause the police to be called to your location?

Noises like these have triggered ShotSpotter alerts. Turn your sound on and take the quiz.
Choose One
  1. Firework
  2. Jackhammer
  3. Truck Door Slamming
  4. Gunshot

What ShotSpotter Claims

Claim #1

ShotSpotter claims it improves relationships between police and communities.

The Truth

ShotSpotter increases the number of high-intensity interactions between police and civilians.

Claim #2

ShotSpotter claims it reduces gun violence.

The Truth

ShotSpotter does not have a significant impact on gun violence.

Claim #3

ShotSpotter claims it improves officer efficiency by telling them the location of gunfire.

The Truth

ShotSpotter rarely finds actionable evidence, reduces 911 calls for service, and ties up officer time.

Claim #4

ShotSpotter claims to be an affordable option for cities.

The Truth

ShotSpotter costs up to $90,000 per square mile - the tech rarely locates actionable evidence and doesn’t reduce gun violence, wasting taxpayer dollars.

Claim #5

ShotSpotter claims to be a gunshot detection program.

The Truth

ShotSpotter is a loud noise detection program that often mistakes loud noises such as fireworks, jackhammers, and car backfires as gunshots.

Claim #6

ShotSpotter claims its technology is 97% accurate with a false positive rate of less than 0.5%.

The Truth

ShotSpotter’s accuracy rate is based on an assumption that 100% of its published alerts are gunfire unless police report otherwise. Of departments that self-report, false positive rates are as high as 48%.

Claim #7

ShotSpotter claims its technology only records “impulsive bang, boom, pops.”

The Truth

ShotSpotter has recorded more than loud sounds - it has captured voice recordings of people on the street that have been admitted as court evidence.

Shotty Statements

Responses to commonly used statements from ShotSpotter, Inc. and its executives.

Responses to Fact-Checked Claims

Misleading Statement on Missed Gunfire

What complicates the gun violence issue further is the fact that a full 80-90% of gunfire incidents go unreported via traditional 911 calls for service. This fact has been independently documented and researched and reported on by the esteemed Brookings Institution.

Ralph Clark, CEO of ShotSpotter Chicago Committee on Public Safety, November 12, 2021

ShotSpotter Statement is Not Proven or Validated.

The Brookings Institution study did not validate ShotSpotter’s ability to differentiate between loud noises. Instead, it used ShotSpotter’s self-reported alert numbers to compare against 911 calls for service.

Note: Gunshots separated by 9 seconds or more are counted as separate ShotSpotter alerts. Two gunshots 9 seconds apart would likely be perceived by a witness as one incident – they would call 911 once. ShotSpotter will use these two alerts (vs. one 911 call) to inflate their statistics of gunfire that goes unreported via 911.

Incorrect Statement on Secretly Recording Other Sounds

We only record impulsive bang, boom, pops, so we’re not recording voices and other sounds such as that.

Regan Davis, Senior Vice President, Customer Success and Field Engineering, ShotSpotter Houston Public Safety and Homeland Security Committee, November 18, 2021

ShotSpotter Statement Is Historically False.

ShotSpotter sensors, which are in unknown locations, are always recording. Prosecutors have submitted audio of voices picked up from ShotSpotter recordings on at least two occasions.

Statements about “97% Accuracy” are Marketing, Not Science

It’s certainly a fact that there hasn’t been an academic peer-review of the service, but I would push back in saying it hasn’t been analyzed. It’s been analyzed for twenty years across 100+ customers that are using it every single day.

Ralph Clark, CEO of ShotSpotter BBC Newsnight: ShotSpotter: What is gunshot detection technology and is it effective?

ShotSpotter Has No Independent Analysis or Testing.

ShotSpotter has never been independently validated/tested for its ability to accurately distinguish among various loud noises. Rather than test its technology, ShotSpotter starts with the assumption that 100% of its published alerts to police are gunfire and only reduces this number as officers self-report false positives (of the few departments that report, false positive rates have been as high as 48%). Legislators are willing to spend millions of taxpayer dollars on unproven tools to appear as if they are addressing gun violence.

The Human Cost of ShotSpotter

Michael Williams
Charles Rex Arbogast/AP

Chicago, IL

Michael Williams

Michael Williams was wrongfully arrested and charged with the murder of Safarain Herring. Prosecutors had no witnesses and no weapon - the case rested primarily upon an impulsive noise detected by ShotSpotter, which was originally labeled by the algorithm as a firework. Williams, later freed, spent nearly a year in jail, suffering from two COVID-19 infections.

On May 31, 2020, Safarain Herring (gunshot wound to his head) was dropped off at St. Bernard hospital by Michael Williams, who was later arrested and charged with Herring’s murder. At 11:46pm, video surveillance showed Williams’ car stopped at the 6300 block of South Stony Island Avenue. At that exact time, 19 ShotSpotter sensors detected a sound that was initially classified as a firework. A ShotSpotter analyst overrode the algorithm and classified the sound as a gunshot. According to Brendan Max, Williams’ attorney from the Cook County Public Defender Office, “The police had no witness who said that they saw Michael shoot anyone, they had no weapon, they had very little evidence in this case other than a ShotSpotter alert which directly led to him being charged and incarcerated in this case.”

Max requested more information regarding ShotSpotter’s training for its forensic experts and the company acknowledged in court filings that “no official or formal training materials exist for our forensic experts.” Williams’ case was eventually dismissed due to insufficient evidence, which ShotSpotter maintains was due to the gunfire being inside a car. ShotSpotter has tried to have it both ways, stating that they had warned prosecutors not to trust the technology’s ability to detect gunfire in a vehicle and that under “certain conditions” the technology can detect gunfire inside vehicles. Williams spent nearly a year in jail.

Silvon Simmons
Lindsay DeDario/REUTERS

Rochester, NY

Silvon Simmons

Silvon Simmons, after being stopped in a car that was wrongly identified by police, was shot in the back by a Rochester police officer. ShotSpotter’s algorithm initially classified the noise as a helicopter, but upon a request to review by Rochester PD, ShotSpotter analysts reclassified the sounds as three gunshots and further increased the number of gunshots on two subsequent reviews (to four and five shots, respectively). ShotSpotter, Inc. refused to turn over the audio recordings to Simmons’ defense team for a reasonable price and Judge Christopher Ciaccio ultimately ruled the decision to convict Simmons was a mistake, in part due to the unreliability of ShotSpotter. Simmons, an innocent man, spent 18 months in jail.


Why do 100+ cities/counties use ShotSpotter if it’s so ineffective?

Technology and automation have helped society progress in so many areas of our daily lives - it’s natural for companies to try and fill that void for police even when they aren’t the solution.

Are there any privacy concerns for my constituents?

We know that ShotSpotter can record voices on the street that could later be used in court. Prosecutors have twice, to our knowledge, tried to submit voice recordings as evidence, and one of them succeeded.

What about the contracts? What are the company’s legal promises to cities?

The only promises ShotSpotter makes to cities are detection/location, the time it takes to publish an alert, and system availability.

Associated graphic

Who owns the data, ShotSpotter or the client (city/law enforcement agency)?

ShotSpotter owns the data, not the cities. ShotSpotter provides its clients with access to the data as long as the contract remains active. Further, they take steps to impede the release of data for independent research and oversight. ShotSpotter technology, paid for with public tax dollars, is often not available to the public nor easily accessible or affordable for independent research evaluations.

Latest News

Durham ShotSpotter scheduled to launch in less than 2 months, community still raising concerns

Durham ShotSpotter scheduled to launch in less than 2 months, community still raising concerns

Durham officials are proceeding with a plan to go live with ShotSpotter, despite continued concerns from community members and local clergy.
Read Article
Cleveland should cancel its ShotSpotter contract, not expand it: LaTonya Goldsby

Cleveland should cancel its ShotSpotter contract, not expand it: LaTonya Goldsby

LaTonya Goldsby, President of Black Lives Matter Cleveland, explains why the city of Cleveland should reject the proposed $2.7M expansion of ShotSpotter and invest this money in the community.
Read Article
Popped volleyball triggers ShotSpotter alert Tuesday in east Toledo

Popped volleyball triggers ShotSpotter alert Tuesday in east Toledo

Young children in Toledo came face to face with police when their volleyball popped and triggered a ShotSpotter alert.
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Tell your local officials to #CancelShotSpotter

Tell your city/county leadership that ShotSpotter has no place in our neighborhoods. ShotSpotter does not prevent gunfire, wastes resources, and does nothing to make us safer. Gun violence is a serious problem - we demand investments in solutions, not private corporations.

These contracts can be terminated at any time. Cancel the contracts.