Aurora considers renewing ShotSpotter service for three years

Chicago Tribune

08-08-2025

Aurora is considering renewing its ShotSpotter service, which detects gunfire within a certain area, for the next three years.
The service by SoundThinking, Inc., has been used in Aurora since it was first approved by the Aurora City Council in 2022. Aurora Deputy Police Chief Steve Stemmet recently told the Aurora City Council's Committee of the Whole that the system has proven itself over the past three years.
'With the almost immediate notification of gunfire and the exact location where it occurred, we are able to significantly decrease our response time to these events,' he said at the meeting.
The three-year service agreement, which would cost the city $140,000 per year for a total cost of $420,000, now goes before the Aurora City Council at its meeting on Tuesday for final approval. The item was placed on the meeting's consent agenda, which is typically used for routine or non-controversial items that are all approved with one vote, often without discussion.
Roughly two square miles of Aurora is covered by ShotSpotter, Stemmet told the Committee of the Whole, but the coverage areas are not exactly divided into square miles. Instead, he said the areas have jagged borders, allowing the service to cover certain neighborhoods or other areas that historically have more gunfire while leaving out those that have not.
While the Aurora Police Department does not publicly release where its coverage areas are, according to Stemmet, he did say that around 40% of all confirmed shootings since 2022 have taken place within those two square miles, which represents just 4% of the city's total land.
'I think that represents that we incorporated the ShotSpotter technology in the correct area based on our own research of decades of shooting incidents,' he said.
Within the coverage areas, ShotSpotter uses AI to detect any gunfire of .25 caliber or higher and then triangulates its location using sensors set up throughout the area, Stemmet said. Within 60 seconds, the sound is sent to an incident review center, where people review the audio then send the information to dispatchers and directly to officers' smartphones and squad car laptops, which allows police to respond 'almost immediately,' he said.
When sent the information, police officers are able to see how many shots were fired and a map of the shooting's location within an 82-foot radius so they can look for evidence of the shooting, like shell casings or a discarded firearm, along with victims or suspects, according to Stemmet.
Officers can also listen to the audio themselves so they can determine what type of gunfire had taken place, which may change response and tactics, he said.
Multiple instances of gunfire can also be shown on the map together, which may show officers that a shootout was happening or show the direction that a shooter was traveling in while shooting, such as in a drive-by situation, which can help locate suspects, Stemmet said.
Using the ShotSpotter service, Aurora police have made 25 arrests, seized 22 firearms and recovered 749 shell casings from shootings, according to Stemmet. He said the recovered firearms and shell casings can be put into forensic databases so they can be linked to other shootings and suspects.
Outside of the coverage area, when the Aurora Police Department gets calls about shots fired, people report they heard gunfire or maybe something that sounds similar then give a general area that could span several blocks, Stemmet said. Sometimes multiple people call in and report different areas, he said, which may further broaden the crime scene even more.
'This obviously makes it almost impossible for officers to locate anything, unless we have a victim calling to report damaged property or injuries,' he said. 'And that's if we get a call at all.'
ShotSpotter has shown over the past three years that nearly half of all shooting instances within the coverage areas go unreported, Stemmet said.
The Aurora Police Department is exploring options to possibly expand the service another square mile sometime in the future, according to Stemmet. He said that research has already been done on where exactly that extra square mile would cover.
According to a staff report about the proposed three-year extension, Soundthinking is the only provider of ShotSpotter and 'the only company that has such a proprietary product,' and so the item was not competitively bid.
ShotSpotter's use in other communities has been controversial, including in Chicago, where current Mayor Brandon Johnson campaigned against and later ended the city's contract for the technology over criticisms of its cost and effectiveness despite a Chicago City Council vote to keep it, according to reporting from the Chicago Tribune.
The Associated Press in 2021 investigated how the technology landed a Chicago grandfather in jail after it was used as evidence to charge him with murder, with a judge later dismissing the case due to insufficient evidence.
Plus, the MacArthur Justice Center has sued Chicago over its use of ShotSpotter, with the organization's webpage dedicated to information about the lawsuit questioning the system's accuracy, especially in cases that led to arrests or other police actions, and saying that it disproportionately covered areas with predominantly Black and Latino residents.
When asked by Ald. Keith Larson, at-large, at the recent Aurora City Council Committee of the Whole meeting about false-positive reports, Stemmet said ShotSpotter does occasionally pick up fireworks, cars backfiring or even nail guns being used, though those reports are 'few and far between.' Police would rather respond to something that is not gunfire instead of missing gunfire when it does happen because it isn't reported, he said.
Plus, people also call 911 to mistakenly report gunfire when they hear similar sounds, he said, but ShotSpotter allows police to clear out those reports in half the time or less as compared to a typical 911 call because the system gives a specific location where it believes the incident happened.