May 16, 2024
To: President Carrie Hartman and members of City Council
Through: Wade Kapszukiewicz, Mayor
Karen Poore, Deputy Chief of Staff
From: Michael C. Troendle, Chief of Police
Subject: Referral #080-24, dated May 3, 2024
REFERRAL:
Error Rate, Efficacy and Benefits of Shot Spotter
Failures of Technology
RESPONSE:
Please see attached document for the following ShotSpotter stats for the last year (May 2023-end of April 2024):
• Detection Summary
o Total Detections Reviewed- Total number of ShotSpotter detections reviewed by ShotSpotter
o Total Detections Published- Total number of ShotSpotter detections that officers were dispatched
o Total Detections Dismissed- Total number of ShotSpotter detections that were dismissed for various reasons ranging from fireworks, construction sounds, to other non-gunfire sounds.
• Gunfire Incident Details
o Single Gunshot
o Multiple Gunshots
o Probable Gunshots
• Agency/Customer Reported Issues- These were errors that were reported by TPD to ShotSpotter
o Reported False Positive Incidents- Incidents that were reported as gunfire and turned out to be non-gunfire related
o Reported False Negative Incidents- Incidents that were not reported to be gunfire but ended up being gunfire related
o Reported Missed Incidents- Incidents that didn’t get picked up by ShotSpotter but evidence of gunfire was found/reported to 911.
o Reported Duplicate Incidents
o Reported Mislocated Incidents- Incidents that occurred and dispatched but location was incorrect.
• Publication Time Metric
o # of Published Incidents Under 60 Seconds- ShotSpotter incidents pushed to dispatch in under 60 seconds.
o # of Published Incidents Over 60 Seconds- ShotSpotter incidents pushed to dispatch later than 60 seconds.
Shotspotter benefits:
• Enables rapid response to gunfire, 80% of which is not reported to 9-1-1
• Over 90% of Shotspotter calls dispatched in less than 60 seconds
• Display gunshot locations on maps in real-time
• Gunshot crime scenes are often not located without Shotspotter and evidence/shell casings missed or not found
• Crime scene accuracy is less than 82 feet from where shots were fired allowing officers a faster, precise response
• Ability to locate gunshot victims sooner, potentially save lives
• Improve evidence recovery and NIBIN leads. Uncover linkages across people, places, and events
• Officer Safety- Provide patrol officers situational awareness for responding to shooting incidents
• Investigative Lead Summary (ILS)- A shooting summary report for court that provides data on the location, sequence and timing of each round fired in a gun shooting incident
Cons:
• Cost- Approximately $280,000 per year for 4 square miles. Equates to about $8.00 per hour, per square mile.