By Dennis Mares and the Center for Crime Science and Violence Prevention

ShotSpotter’s gunshot detection system was deployed in Winston-Salem in August 2021. Since then, nearly 2,000 alerts received a response by Winston-Salem Police.

Results indicate: 

• Improved response to gunfire

  • The response to alerts is significantly quicker than those called in by residents (- 5 min.).

  • ShotSpotter calls received significantly more investigative time, which likely indicates improved evidence recovery.

  • Fewer than one in four ShotSpotter alerts also received a call from residents.

• ShotSpotter produces the following actionable results:

  • Shell casings were recovered in 581 incidents (37.1%)

  • Firearms were recovered in 47 (3%) of alerts.

  • Sixty-seven (3.4%) gun-related arrests are connected to alerts. 

• Deployment of ShotSpotter is related to a reduction in violent gun crimes:

  • Aggravated assaults are down 26% comparing before-after results in the ShotSpotter area.

  • Comparable area and overall city numbers indicate an increase in aggravated assaults during the same period. Comparatively assaults are down 38% in the ShotSpotter community.

  • In real numbers, there are between 51-75 fewer assaults annually in the ShotSpotter area than would be expected. 

• Cost-Benefits:

  • Our estimate suggests that ShotSpotter may save the Winston Salem community between $5 and $8 Million annually.

  • Average annual implementation cost is estimated between $230,000-350,000

  • This indicates a $15-25 return for each dollar spent.

Edwardsville, IL: Southern Illinois University, Center for Crime Science and Violence Prevention, 2024. 27p.

By Eric L. Piza, David N. Hatten, Jeremy G. Carter, Jonas H. Baughman, George O. Mohler

Gunshot Detection Technology (GDT) is expected to impact gun violence by accelerating the discovery and response to gunfire. GDT should further collect more accurate spatial data, as gunfire is assigned to coordinates measured by acoustic sensors rather than addresses reported via 9-1-1 calls for service (CFS). The current study explores the level to which GDT achieves these benefits over its first five years of operation in Kansas City, Missouri. Data systems are triangulated to determine the time and location gunfire was reported by GDT and CFS. The temporal and spatial distances between GDT and CFS are then calculated. Findings indicate GDT generates time savings and increases spatial precision as compared to CFS. This may facilitate police responses to gunfire events and provide more spatially accurate data to inform policing strategies. Results of generalized linear and multinomial logistic regression models indicate that GDT benefits are influenced by a number of situational factors.

Policing: A Journal of Policy and Practice. https://doi.org/10.1093/police/paac097 , 2023 38p.