POP Center Responses Gunshot Detection Appendix A
Appendix A: Studies Exploring Acoustic Gunshot Detection Systems’ Efficacy to Reduce Gun Violence
City | Years and Type | Targeted Offense | How Effective | Research Design | Studies |
St. Louis, Missouri | 2006–2009 ShotSpotter | Part I Gun Offenses | No significant effects. Reductions and increases occurred randomly in both experimental and control sites | Interrupted time-series | Mares and Blackburn (2012) |
Philadelphia, Pennsylvania | 2015–2016 SENTRI sensors with CCTV | Gunshots calls for service | 259% increase in gunshot notifications, but no significant increase in founded incidents | Block randomized controlled experiment, multi-level difference-in-difference | Ratcliffe et al. (2018) |
Denver, Colorado | 2008–2016 ShotSpotter | Gun crime calls for service and Part I crimes | No significant changes in crime levels or calls for service | Quasi-experimental interrupted time-series | Lawrence, La Vigne, and Thompson (2019) |
Milwaukee, Wisconsin | 2008–2016 ShotSpotter | Gun crime calls for service and Part I crimes | Significant increases in gun crime calls for service; no significant reductions in reported gun crimes | Quasi experimental interrupted time-series | Lawrence, La Vigne, and Thompson (2019) |
Richmond, California | 2006–2015 ShotSpotter | Gun crime calls for service and Part I crimes | Significant increases in gun crime calls for service; no significant reductions in most restrictive models but some in less restrictive models (around 30%) | Quasi experimental interrupted time- series | Lawrence, La Vigne, and Thompson (2019) |
St. Louis, Missouri | 2005–2018 ShotSpotter | Calls for service for gunfire and gun violence | Significant reductions in gunfire calls for service; some reduction in gun violence initially but none significant | Quasi-experimental multi-level difference-in-difference | Mares and Blackburn (2021) |
68 Metropolitan Counties | 1999–2016 ShotSpotter | Gun homicides, gun arrests, homicide arrests | No significant reductions in any metrics | Cross-sectional time series analysis | Doucette et al. (2021) |
Wilmington, Delaware | 2014–2020 ShotSpotter/CCTV integration | Homicides and shootings | No significant reductions | Interrupted time-series analysis | Vovak et al. (2021) |
Cincinnati, Ohio | 2015–2020 ShotSpotter | Calls for service shots fired and reported Gun assaults | Significant reductions (45% in shots fired and 46% in gun assaults) | Block matched quasi-experimental multi-level difference-in-difference | Mares (2021a) |