A Cost-Benefit Analysis of Shotspotter in Winston-Salem, NC: Improving the Police Response to Gunfire

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.