Protesters march during a July 2021 protest, calling on the city to cancel its ShotSpotter contract. (Credit: Mauricio Peña/Block Club Chicago)
Protesters march during a July 2021 demonstration, calling on the city to cancel its ShotSpotter contract. (Credit: Mauricio Peña/Block Club Chicago)

If Mayor Brandon Johnson follows through on his promise to end Chicago’s multimillion dollar contract with SoundThinking — the company behind ShotSpotter acoustic gunfire sensors — it will be the largest city to drop a contract with the company in its 26 year history.

Johnson had vowed during the mayoral campaign that he would cancel the contract but in recent weeks has stopped short of confirming that commitment. If he does, he might consider what happened in cities like Dayton, Ohio, when they ended their ShotSpotter contracts.

After Dayton signed a contract in July 2019 to install about 60 ShotSpotter acoustic sensors surrounding a predominantly Black neighborhood on the Northwest Side of the city, police brass initially liked what they saw. 

Dayton police received more than 2,200 ShotSpotter alerts in the first two years of the program, specifying where sensors determined that a gunshot had been fired. A commanding officer with the Dayton Police Department told local radio station WYSO that dispatching cops to those 2,200-odd locations had a positive side effect of making cops more visible: “The community sees us out there, they see us responding to gun crime,” the officer said in October 2021. 

But visibility can be tough to measure. And other metrics for ShotSpotter in Dayton didn’t look so rosy.

Out of 8,043 total rounds detected by ShotSpotter sensors over nearly three years in Dayton, police made only 74 arrests related to those dispatches, according to James Rider, a Dayton police spokesman. That means an arrest happened in less than 1% of the dispatches prompted by a ShotSpotter alert in Dayton. To complicate matters, Ohio Gov. Mike DeWine signed a 2022 bill into law allowing Ohio citizens to carry concealed firearms without a permit, which made going after gun crimes more difficult for Ohio cops, even with a ShotSpotter alert. 

So in October 2022, when police brass in Dayton weighed whether to extend the contract for three years for  $615,000, they ultimately passed, citing ShotSpotter’s own data, the response from the community and officers, as well as the change in state law.

It’s not every day that a city breaks ties with SoundThinking, the nation’s leading acoustic gunshot detection company that recently rebranded from ShotSpotter Technologies, Inc. The publicly traded entity behind the ShotSpotter sensors claimed in a recent filing with the U.S. Securities and Exchange Commission that it’s under contract with “over 151 cities” and 19 college campuses.

The number of cities that have chosen to end their relationship with ShotSpotter is, according to an Illinois Answers analysis, quite low. Dayton and Canton, Ohio, have ended their contracts with SoundThinking, though Canton shifted to a ShotSpotter competitor, Blueforce, rather than eliminate gunshot sensors. Atlanta has decided against ShotSpotter sensors after two experimental trials in 2018 and 2022. New Orleans ended its relationship with ShotSpotter in 2013. Trenton, New Jersey declined to renew its ShotSpotter contract in 2016. Charlotte, San Antonio, Troy, New York, and Fall River, Massachusetts, also backed out of contracts. Portland’s mayor announced Thursday that the Oregon city would not move forward with its plans to install ShotSpotter devices. And that’s about it. 

An analysis comparing ShotSpotter use with homicide data in the cities that have ended ShotSpotter contracts shows no clear overall trend of a reduction in homicides before or after the cities implemented the sensors. 

Chicago experimented with a ShotSpotter trial in the late 2000s and quietly ended the experiment without a contract.   

In 2018, the city reversed course and signed a $33 million, three-year contract with ShotSpotter’s parent company, initially set to expire in 2021.

The city was in the midst of that contract when Lori Lightfoot’s administration quietly extended it by two years. The contract is now set to expire on February 16, 2024, after a second quiet extension by the Lightfoot administration this year.

“This contract is a bigger deal for [SoundThinking] than it is for Chicago,” said Freddy Martinez, director of Lucy Parsons Labs, which has compiled voluminous data about Chicago’s use of gunshot detection tech in Chicago. It joined a lawsuit against the city for unlawful police stops and false charges, and has called for the city to end its contract with ShotSpotter. “It’s not a big deal in terms of the city’s spending.”

While what the city is spending with SoundThinking amounts to well under .1% of the city’s $16.7 billion overall 2022 budget, SoundThinking’s revenues in 2022 were just over $81 million, and Chicago’s contract alone accounts for about 11% of those revenues. It’s the company’s second largest contract behind New York City. Which is why the company’s stock price dropped by more than 20% when Chicago elected Johnson as its next mayor. 

Like stakeholders in Dayton, Ohio, Brandon Johnson has plenty of data to inform his promise to end Chicago’s SoundThinking contract. A much-cited report from Chicago’s inspector general “does not support a conclusion that ShotSpotter is an effective tool in developing evidence of gun-related crime.” Among the IG’s findings: Only 9.1% of more than 50,000 ShotSpotter alerts turned up evidence of a gun-related criminal offense having occurred.

An analysis by the MacArthur Justice Center found similar numbers of 40,000 so-called “dead-end police deployments” in Chicago, data cited in the lawsuit it spearheaded against the city for allegedly jailing a man for a shooting he did not commit based in part on “unreliable” evidence from a ShotSpotter sensor. That’s in addition to Chicago having more homicides in 2021 — in the midst of its ShotSpotter contract — than any year in the last quarter century.

Those facts and figures make for an easy decision for Johnson and Chicago in Martinez’s view. “[ShotSpotter] is not working,” he says. “And I don’t know if it’s going any better.”

A spokesman for Johnson did not respond to requests to discuss ShotSpotter’s future in Chicago, but Johnson adviser Jason Lee told the Sun-Times in an article on May 26 that the mayor is in no rush to end its relationship with SoundThinking prior to the end of the current contract. 

SoundThinking executives say the findings from Chicago’s IG and others cherry-pick data.

“Although 10% might sound small, you have to look at the nominal number of what’s in that 10%,” SoundThinking CEO Ralph Clark told WTTW in reference to the Chicago IG’s findings. “We know from looking at the same data that the OIG report produced, ShotSpotter led to 1,100 gunshot-wound victims coded by the data that OIG looked at. Eight hundred of those 1,100 gunshot-wound victims did not have a corresponding 911 call. It means that ShotSpotter was the means by which first responders got to those folks that were potentially bleeding out and potentially saving a percent of those lives.”

Clark’s colleague, Tom Chittum, SoundThinking’s senior vice president for analytics and forensic services, underscored the same point with Illinois Answers. “The most important measure is how many gunshot wound victims have you been able to locate?” Chittum then referenced a Brookings Institute report finding that 80% of gunfire incidents aren’t reported through 911 call systems. “That’s one out of five opportunities that police have to try and catch somebody for doing something.”

Chittum wouldn’t speak directly about Chicago. (Clark has said he’s “optimistic” that Johnson will decide to keep the city’s ShotSpotter contract.) But Chittum said that the technicalities wouldn’t be difficult if the city decides to end its contract.

SoundThinking considers itself a “software-as-a-service” company — meaning that it doesn’t sell its ShotSpotter hardware to cities; it markets the software and apps police can use for ShotSpotter alerts. So Chicago doesn’t own sensors that it would need to take down or find another use for. SoundThinking will simply retrieve the sensors and move on. 

Ultimately, Chittum stressed that analyses from Chicago’s IG and others overcomplicate matters. “From our perspective, one of the most important things our customers can do is prioritize response to our alerts,” he said. “Evidence is ephemeral. Gunshot wound victims need fast aid and the sooner you get out there and can assess, the sooner you can dispatch other services.”

The Dayton police department  decided that ShotSpotter sensors weren’t necessary. Rider, the police spokesman, pointed out that the area of the city with ShotSpotter sensors “saw a 55% reduction in all crime categories” while a control area without the sensors only decreased by 37%. 

“ShotSpotter is only one of many tools used to respond to these types of incidents, and DPD has implemented beat officers in all areas of the city to address violent crime moving forward,” Rider said. “With the cancellation of this contract, DPD does not plan on utilizing gunshot detection technology at this time.”

A former correspondent with The Associated Press and Bloomberg News, Matt’s writing has been featured in Esquire, Politico, The Verge, and a slew of other media outlets. The New York Times called his book, “Thin Blue Lie: The Failure of High-Tech Policing” an “incisive, muckraking expose of the police industrial complex,” and his six-part, true crime podcast, “Guru: The Dark Side of Enlightenment” hit #1 on Apple Podcast charts in 2020.

Several of his investigative reports have led to new trials in murder cases, and his other work has preempted federal investigations, caused CEO resignations, and inspired legislative change.