ShotSpotter microphones are controversial surveillance devices designed to alert authorities to gunshots. But their exact locations have been kept secret from both the public and the police—until now. WIRED obtained leaked documents detailing the locations of over 25,500 of these devices, and what we learned abut how and where they’ve been deployed may surprise you.
Have data or information you'd like to share with WIRED? You can reach out securely via email at dhruvmehrotra@wired.com or on Signal at dmehro.89
Director: Lisandro Perez-Rey
Director of Photography: Constantine Economides
Editor: Matthew Colby
Host: Dhruv Mehrotra
Line Producer: Joseph Buscemi
Associate Producer: Paul Gulyas; Brandon White
Production Manager: Peter Brunette
Camera Operator: Chris Eustache
Sound Mixer: Sean Paulsen
Production Assistant: Ryan Coppola
Post Production Supervisor: Christian Olguin
Post Production Coordinator: Ian Bryant
Supervising Editor: Doug Larsen
Assistant Editor: Fynn Lithgow
Have data or information you'd like to share with WIRED? You can reach out securely via email at dhruvmehrotra@wired.com or on Signal at dmehro.89
Director: Lisandro Perez-Rey
Director of Photography: Constantine Economides
Editor: Matthew Colby
Host: Dhruv Mehrotra
Line Producer: Joseph Buscemi
Associate Producer: Paul Gulyas; Brandon White
Production Manager: Peter Brunette
Camera Operator: Chris Eustache
Sound Mixer: Sean Paulsen
Production Assistant: Ryan Coppola
Post Production Supervisor: Christian Olguin
Post Production Coordinator: Ian Bryant
Supervising Editor: Doug Larsen
Assistant Editor: Fynn Lithgow
Category
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TechTranscript
00:00These controversial surveillance devices are designed to alert authorities to gunshots,
00:05and their exact locations have been kept hidden from police and the public.
00:08Until now.
00:09Wired obtained leaked documents that reveal for the first time the secret locations of
00:1325,580 shot spotter microphones.
00:17In this video, we'll analyze that data and test the claim of activists that these sensors
00:21lead to biased over-policing of communities of color across America.
00:2512 million Americans live in a neighborhood with at least one shot spotter microphone.
00:30Are you one of them?
00:31Let's put shot spotter secret locations on the grid.
00:39This is just one of the 25,580 data points that represent shot spotter microphone locations,
00:46as indicated in the leaked documents provided to me earlier this year by a source under
00:50the condition of anonymity.
00:51To confirm that the leaked data was legit, Wired vetted the locations by physically
00:55visiting sensors in different cities, including Pasadena, California, Chicago, Illinois,
01:01I think that's it on top of the pole.
01:03Miami, Florida.
01:04There it is.
01:05I see it.
01:06And this one, attached to a street lamp near Prospect Park in Brooklyn, New York, where
01:10we spotted the protective casing that houses the acoustic sensors and processors.
01:15We even used Google Street View to virtually visit a random sample of locations in the
01:19document.
01:20And they check out.
01:21The sensors were exactly where the leaked data said that they would be.
01:25We don't know if our dataset includes all sensors that exist, but Tom Chittum from Sound
01:29Thinking, the company that makes them, said that as of February 2023, the document was
01:34likely authentic.
01:36The dataset represents over 1,000 elementary and high schools, dozens of billboards, scores
01:41of hospitals, and more than 100 public housing complexes where the sensors are placed.
01:45In total, the leaked document indicates shot spotter locations in 84 metropolitan areas
01:51across 34 states, plus U.S. territories such as Puerto Rico and the Virgin Islands.
01:56Nine U.S. cities actually have more than 500 sensors installed, including Albuquerque,
02:01New Mexico, Chicago, Illinois, Las Vegas, Nevada, and Washington, D.C., where sensors can be
02:09found on U.S. government buildings, including the headquarters of the FBI, the Department
02:14of Justice, the U.S. Court of Appeals, and just outside the city, throughout the campus
02:18of the University of Maryland.
02:20So why are specific locations chosen for shot spotter?
02:24According to Tom Chittum, when police departments purchase Sound Thinking's services, they
02:28provide the company with data about gun violence in the area.
02:32Once a plan is agreed upon by the department, Sound Thinking will seek permission from private
02:36property owners, utility companies, and business owners to install sensors on their premises.
02:44While Chittum says that most property owners agree to do so without needing incentivization,
02:49the company will occasionally offer gift cards to secure access to their private property.
02:53According to the company, if a loud, impulsive sound is heard in the coverage area, sensors,
02:59often on top of buildings and streetlights, pick it up.
03:01The location of the incident is determined by measuring the time the sound takes to travel
03:05to each sensor.
03:06At minimum, three sensors need to detect a sound for it to be flagged.
03:10The sound is then first analyzed by AI to determine if it's likely a gunshot, before
03:15being sent to a shot spotter incident review center, where analysts determine whether it's
03:20gunfire or something else, like a firework or a car backfiring.
03:24If it's a gunshot, ShotSpotter then alerts law enforcement.
03:27Sound Thinking claims they keep the exact locations of their sensors secret, even from
03:31police, to protect people who allow the sensors on their property, as well as to prevent the
03:36mics themselves from being tampered with or vandalized.
03:39But this secrecy has been a point of contention for those who criticize the company.
03:44DPD we want you out!
03:46The ACLU argues that, quote, there are deep problems with the gunshot detection company
03:51and its technology, including its methodology, effectiveness, and impact on communities of color.
03:57So are activists right?
03:58Where are these microphones being placed?
04:00Wire did some digging and found the answer.
04:03After receiving the leaked documents of the sensor locations, we used the most recent
04:07census data and collected the demographic information from every census block group
04:11with at least one Sound Thinking sensor.
04:13Each census block group has between 600 and 3,000 people in it.
04:17We then analyzed sensor distribution in U.S. cities and found that, in aggregate, 70% of
04:22people who live in a neighborhood with at least one Sound Thinking sensor identified
04:26as either black or Latino, nearly three-quarters of these neighborhoods are majority non-white,
04:32and the average household earns a little more than $50,000 a year.
04:35But let's zoom in and look at individual jurisdictions.
04:38The pattern appears to be the same.
04:40Winston-Salem, North Carolina, for example, is approximately 43% white, but only 13% of
04:46residents who live in areas that have at least one ShotSpotter sensor identified as white.
04:51In Fort Myers, Florida, roughly 19% of the population is black.
04:55In block groups with at least one sensor, however, approximately 41% of the population is black.
05:01So Wire's findings do align with the theory put forth by activists and critics that ShotSpotter
05:06surveillance does disproportionately occur in poor communities of color.
05:10Why invest in ShotSpotter when it's shown it doesn't curb gun violence?
05:15It doesn't do what it says it's supposed to do.
05:17So what happens when police answer a call based on a ShotSpotter report in one of these
05:22neighborhoods?
05:23Let's go to Cincinnati, Ohio.
05:24It's New Year's Eve 2022, 8.21 p.m.
05:27Several sensors pick up two loud sounds that could be gunshots.
05:31This is body cam footage that Wire obtained of the incident.
05:34You can see police detaining a man who happened to be standing near the corner where the ShotSpotter
05:38mics detected supposed gunfire.
05:41Nine officers were sent to the location to respond.
05:43However, once there, they found no gun, no bullet casings, no bullet holes, nor any evidence
05:49that a crime had been committed there.
05:51So we kind of did about 10 feet out and it's nothing.
05:54Unless he had a revolver.
05:55Yet cops still arrested this man after they ran his name and found he'd failed to appear
06:00in court for traffic violations.
06:02This incident tracks with the 2021 Northwestern University School of Law study, which found
06:07that over a two year period, 89% of alerts in the city of Chicago did not result in police
06:12finding evidence of a gun related crime.
06:14This is likely at least in part due to how often suspected gunfire alerts end up being
06:19something else entirely.
06:20For example, according to this article, officers in Pasadena responding to scenes of ShotSpotter
06:25alerts have pointed to backfiring cars, fireworks, or even noisy construction as the actual sources
06:31of the sounds the sensors detected.
06:33And that's when the sensors are actually working.
06:37In December 2022, SoundThinking's sensors failed to issue an alert for a shooting at
06:42a Euroshop in Chicago that wounded two men.
06:45Reportedly 55 rounds were fired, yet SoundThinking's equipment sent out no alerts.
06:50The misdetections were apparently due to three out of service sensors.
06:54In fact, according to the leaked document, as many as 357 sensors in the Chicago metropolitan
07:00area were broken, unreliable, or out of service at the time.
07:04That's 9% of the total sensors in the city.
07:072,680 of SoundThinking's sensors nationwide, one in 10, were categorized as either broken,
07:13unreliable, or out of service at the time the file was created, allegedly late last
07:18year.
07:19This past September, Mayor Brandon Johnson, a vocal critic of ShotSpotter, said the city
07:23will not renew its contract with SoundThinking.
07:25On a side note, one interesting use case for ShotSpotter can be found way across the world
07:30in South Africa.
07:31The Kruger National Park, one of the most renowned wildlife conservation areas in the
07:35world, has sensors throughout its grounds, presumably to curb the poaching of endangered
07:40species.
07:41Want to see if there's a ShotSpotter near you?
07:44Click on the WIRED article in this video's description and search the data yourself.
07:48I'm Drew Marotra, thanks for watching On The Grid.