NOTE: The City of Chicago ended its use of ShotSpotter on 9/22/2024. This dataset is historical-only and ends with that date.

This dataset contains all ShotSpotter alerts since the introduction of ShotSpotter to some Chicago Police Department (CPD) districts in 2017. ShotSpotter is a gunshot detection system designed to automatically determine the location of potential outdoor gunfire. ShotSpotter audio sensors are placed in several CPD districts throughout the city (specific districts are noted below). If at least three sensors detect a sound that the ShotSpotter software determines to be potential gunfire, a location is determined and the alert is sent to human ShotSpotter analysts for review. Either the alert is sent to CPD, or it is dismissed. Each alert can contain multiple rounds of gunfire; sometimes there are multiple alerts for what may be determined to be one incident. More detail on the technology and its accuracy can be found on the company’s website here. It should also be noted that ShotSpotter alerts may increase year-over-year while gun violence did not necessarily increase accordingly because of improvements in detection sensors.

ShotSpotter does not exist in every CPD district, and it was not rolled out in every district at the same time. ShotSpotter was first deployed in Chicago in 2017, and sensors exist in the following districts as of the May 2021 launch of this dataset: 002, 003, 004, 005, 006, 007, 008, 009, 010, 011, 015, and 025.