Will Chicago Learn From Its Past Mistakes With ShotSpotter?

Ed Vogel / Jan 16, 2024

Chicago protestors in July, 2021. Mauricio Peña/Block Club Chicago

New research out of Chicago shows that police deployments initiated by the gunshot surveillance technology ShotSpotter result in slower police response times to possible shooting incidents. Based upon their analysis of 911 dispatch data from the Chicago Police Department, University of California Santa Barbara Department of Economics PhD Candidates Michael Topper and Toshio Ferrazares find that “ShotSpotter implementation causes police officers to be dispatched one minute slower (a 23% increase) and arrive on-scene nearly two minutes later (a 13% increase)” than non-ShotSpotter initiated deployments.

This evidence follows other research that discredits ShotSpotter. Research conducted by the MacArthur Justice Center and corroborated by the Office of Inspector General demonstrates that 90% of ShotSpotter-initiated police deployments do not result in evidence of a gun crime. Another recent study of ShotSpotter in Kansas City showed that the technology failed to reduce violent crime there over a three-year period.

With every new study, pressure mounts on Chicago Mayor Brandon Johnson to keep his campaign promise and cancel the City’s contract for the failed technology. The Chicago Police Department (CPD) continues to fail to provide any evidence that ShotSpotter has made an impact on Chicago’s gun violence. Instead, the department continues to defend its use of the technology through unsubstantiated statements of its benefits for public safety. For example, Police Superintendent Snelling claims that “if there’s someone who's been shot, [ShotSpotter] gives us the opportunity to render life-saving aid if we get there ahead of time.”

As the Topper and Ferrazares study shows, ShotSpotter doesn’t actually do that. Moreover, it also subjects marginalized communities to further intrusions, harassment, and violence from police. Prof. Maneka Sinh argues the technology “effectively become a free pass for police to conduct blanket stop-and-frisks of a wide swath of people in the vicinity of an alert.”

At this point, it’s clear that ShotSpotter is a waste of taxpayer money - more than $40 million spent since 2018. Anyone serious about addressing Chicago’s gun violence needs to be honest about that.

Rather than continue the debate about the use of ShotSpotter, we should step back and assess what we can learn from this failed experiment if the goal is not to repeat it. First, when the City signed an initial contract with ShotSpotter, the contract did not require the technology to be independently tested or peer-reviewed. The company has long claimed that ShotSpotter is 97% accurate, but the stat is not substantiated by a study that the company did not solicit and underwrite.

Second, the City did not require any disclosure regarding ShotSpotter’s algorithmic decision-making functionality, which is one of the primary selling points of the company’s “precision policing” claims. Simply put, this is alarming because research on other algorithmically based police surveillance technologies shows that these tools can exacerbate existing issues of racist policing. Of course, trade secret law protects the company’s interest and limits the legal requirement for disclosure, but should the City place the company’s interests above those of residents?

Finally, Chicago never required the police department to determine any metrics to evaluate the performance of ShotSpotter. There also appears to be no system in place to even collect the necessary data to evaluate the efficacy of the system for the community. If there is a system, it has yet to be shared publicly. CPD’s use of ShotSpotter is an unfortunate case study of a government's failure to provide sufficient transparency and accountability mechanisms for a technology that has a direct bearing on the safety and well-being of its residents.

CPD allowed ShotSpotter to treat Black and brown Chicagoans as test subjects for an unproven technology. Even more alarming, is that the city’s negligence is not an isolated incident. It is a pattern with CPD’s surveillance apparatus. Chicago has built one of the largest surveillance systems of any city in the country by spending millions of dollars annually on technologies like facial recognition technology, automated license plate readers, social media monitoring software, surveillance cameras, video analytics software, and body cameras, among other technologies. For example, while the City gives no official count, it is reasonable to estimate that there are more than 50,000 publicly owned cameras deployed across the city, and this does not include the thousands of private cameras integrated into the City’s system.

Despite this significant investment of public resources, the City cannot provide proof that these tools have improved the lives of residents. Worse, it's distinctly possible that these technologies have harmed Chicagoans, particularly Black residents.

Since 2019, at least six people across the country have been falsely accused of committing a crime after a faulty facial recognition scan, including multiple instances with the technology sold by the same vendor CPD uses. CPD has doubled down on the use of license plate readers in response to fears of carjackings, but these cameras often misread plates, leading to potentially dangerous police interactions. Even when these cameras read license plates accurately, CPD is collecting hundreds of millions of data points about the daily life of drivers and inviting nefarious behavior, like an officer in Kansas who used license plate readers to stalk his estranged wife.

It’s clear that the City of Chicago has not learned from its mistakes with ShotSpotter as CPD is currently piloting CrimeTracer, another product from SoundThinking, but this news only came to residents from the company, not from an elected official or those who claim to serve and protect.

Chicago has wrapped itself up in a fear-driven surveillance spending spree with little to show. This pattern should be a cause for concern for every Chicagoan as well as residents of cities across the country using or considering the use of ShotSpotter. If the City does not change how it procures and evaluates policing technologies, we’ll be discussing more failed experiments like ShotSpotter in the years to come.


Ed Vogel
Ed Vogel is a member of the Chicago and National #StopShotSpotter campaigns. He is a Public Voices Fellow on Technology in the Public Interest with The OpEd Project in partnership with The MacArthur Foundation.