Eric L. Piza, Nathan T. Connealy, Rachael A. Arietti, George O. Mohler, and Jeremy G. Carter (2025)
Criminology & Public Policy
Key Takeaways
- A matched quasi-experimental examined how gunshot detection technology (GDT) and CCTV cameras affected case clearance rates for fatal shootings (6,068 cases) and non-fatal shootings (64,884 cases) between 2005-2019 in Chicago
- Neither GDT nor CCTV significantly improved case clearance rates for fatal or non-fatal shootings
- While the primary technologies showed little impact, Chicago’s Strategic Decision Support Centers (SDSCs) were associated with higher odds of clearing non-fatal shooting cases.
- While standalone technologies may not deliver investigative benefits, SDSCs that leverage multiple technologies together may be more effective for improving gun violence case clearance rates.
Research Summary
The current study is a comprehensive evaluation of how gunshot detection technology (GDT) and closed-circuit television (CCTV) surveillance systems affect police case clearance rates in Chicago.
Video surveillance cameras in the current study were deployed beginning in 2005 and included over 5900 unique camera deployments by 2019. The Chicago Police Department (CPD) first deployed GDT in a pilot phase in September 2012, covering an approximately 3-square mile area. In 2017, CPD began extending GDT coverage across the city through ten additional deployment phases (11 total), which brought the coverage area to over 136 square-miles. Mayor Brandon Johnson later terminated the City of Chicago’s contract with ShotSpotter, leading to the GDT system being decommissioned in September 2024.
A matched quasi-experimental design analyzed 6,068 fatal shootings and 64,884 non-fatal shootings occurring between 2005 and 2019 to determine whether these widely adopted technologies actually improve investigative outcomes.
The study employed entropy balancing, a sophisticated statistical matching technique, to create weighted control groups that closely resembled treatment groups across multiple variables. Three treatment conditions were examined: shootings exposed to GDT only, shootings within 500 feet of CCTV cameras, and shootings exposed to both technologies simultaneously. This approach allowed researchers to isolate the specific effects of each technology while controlling for numerous factors that could influence case outcomes.
The results revealed that neither GDT nor CCTV significantly improved case clearance rates for either fatal shootings or non-fatal shootings. While the primary technologies showed minimal impact, the study uncovered an important finding regarding Chicago’s Strategic Decision Support Centers (SDSCs). These integrated facilities, which combine multiple technologies, including GDT, CCTV, and various databases with dedicated personnel and crime analysts, were associated with 19-24% higher odds of clearing non-fatal shooting cases.
The findings align with existing literature showing that CCTV tends to be most effective for less serious crimes like theft and disorder, rather than serious gun violence. Furthermore, the lack of GDT effect on case closure aligns with recent research incorporating similar matched quasi-experimental designs.
The research suggests that standalone surveillance technologies may not deliver the investigative benefits policymakers anticipate from their substantial investments. Rather than deploying technologies in isolation, law enforcement agencies may achieve better outcomes through comprehensive integration platforms that combine technological capabilities with human expertise and strategic coordination. In this sense, increased investment in rigorous testing of Strategic Decision Support Centers, as they appear to offer a promising model for maximizing the utility of multiple technologies in gun violence investigations.
Eric L. Piza, Ph.D. 