Skip to main content

Failures of Predictive Policing: Chicago’s ShotSpotter Program

Posted by on Tuesday, February 20, 2024 in Blog Posts.

By Lauren Szwarc

After facing much criticism, Chicago Mayor Brandon Johnson has finally fulfilled his campaign promise to cancel the city’s contract with ShotSpotter.[1] The ShotSpotter program is a recent technological development in predictive policing that was adopted by the city under Mayor Rahm Emanuel in 2018.[2] The ShotSpotter program functions by placing microphones and audio software in neighborhoods in Chicago that are deemed to be “hot spots” of crime.[3] The technology was intended to alert police once a gunshot was detected at one of the hot spots so the police could quickly respond.[4] However, the program is riddled with inaccuracy and has largely failed to produce evidence of gun crimes.[5] ShotSpotter frequently alerts false positives and, out of the over 50,000 ShotSpotter alerts deployed in 2021, only 9.1% of these alerts provided evidence of a gun-related offense.[6]

One of the prominent issues with predictive policing technology in general is that it results in the over policing of lower-income communities of color. Aside from homicides occurring in certain places, the “hot spot” places where predictive policing is employed are largely artificially created. The more and more an area is policed, the more and more crime statistics are going to increase for that area; however, this does not necessarily mean that an area is a “high crime zone,” this just means this is an area where police are deciding to enforce the law. By continually surveilling and targeting the same communities of people, the police are only further entrenching poverty and crime in these areas. Once someone is arrested, it is highly likely that they will continue to interact with the criminal justice system in the future, especially when they are being placed back into heavily surveilled environments.

Furthermore, the ShotSpotter program has also given police free reign to search and seize the people who lived in these communities. Under Terry v. Ohio, an officer is allowed to conduct a limited search for weapons when they have reasonable suspicion that one is armed and dangerous.[7] Therefore, when the police show up at locations ShotSpotter has alerted them to, they are entitled to stop and frisk people in the surrounding vicinity due to concerns of officer safety.[8] Thus, people can be arrested for possessing drugs or for carrying guns as convicted felons which were uncovered during the course of constitutional stop and frisks made possible by ShotSpotter.

Lauren Szwarc is a current 2L at Vanderbilt Law School. She plans to pursue a career in litigation following  graduation.

[1] See Heather Cherone, Mayor Brandon Johnson Cancels ShotSpotter Contract, Fulfilling Major Campaign Promise, WTTW News (Feb. 13, 2024),

[2] See id.

[3] See Fola Akinnibi, NYC, Chicago Waste Millions on Gunshot Detection Technology, Report Says, Bloomberg (July 14, 2022),

[4] See id.

[5] See Liz Nagy, Chicago ShotSpotter Technology Contract to Last Through at Least Late September, ABC7 Chicago (Feb. 16, 2024)

[6] See id.

[7] See Terry v. Ohio, 392 U.S. 1, 24 (1968)

[8] See id. at 10–11.

Tags: , , , ,