A closer look at ShotSpotter as Detroit weighs decision to expand
(CBS DETROIT) - While Detroit continues to consider expanding ShotSpotter in the city, we took a closer look at data from two cities using the technology--St. Louis and Cincinnati-- to get a better idea of its impact on crime.
The two cities are among nearly 150 cities across the country that have turned to gunshot detection technology as a way to address gun violence, but not without controversy. Over the years, many people have questioned if ShotSpotter is effective.
To this day and depending on who you talk to, the jury is still out.
"We did not find any impact on violent crime," said Dennis Mares, a professor at Southern Illinois University Edwardsville.
Mares co-authored a study that reviewed ShotSpotter data in St. Louis from 2008 to 2018.
"We looked at gun homicides and aggravated assaults with firearms and there we did not find any reductions compared to similar neighborhoods without ShotSpotter and Saint Louis."
He also did a similar study in Cincinnati and reviewed ShotSpotter data from when it launched in 2017 to 2020. Mares' findings were much different than St. Louis, albeit a smaller sample size.
"We did find a substantial reduction of violent crime around 40% of gun violence in the areas it was implemented," he said.
Cincinnati Police also said the city saw 79 less shootings in 2021 (486) compared to 2020 (405) although homicides stayed the same.
For Mares, this doesn't mean Cincinnati is a success and St. Louis is a failure because other crime-fighting strategies could be a reason metrics improved or worsened.
But he does believe it's a valuable tool both cities have benefited from with it helping decrease police response times and assisting in investigations.
Cincinnati Police Department's Lt. Col. Michael John can attest to that, saying the technology can save lives.
"There have been incidents where we've got to the scene much, much quicker than we would have if we were waiting for somebody to call 911," he said.
But like with any technology, he said it is far from perfect.
"I read every single shooting report that is generated in the city and there were occasions where I knew that the person shot was being shot by the territory and there was no associated activation," he said.
In the end, John said he would recommend ShotSpotter for police departments. He believes the good that comes with it outweighs the bad.
Mares agrees. He said ShotSpotter as a tool is only as good as the people using it.
"I think that if we want to make ShotSpotter successful, we have to think about what does it take to make that successful?, Mares said. "The technology side is one thing, so you can have all the perfect data where gunfire happens. But if you don't respond quick enough or you don't investigated thoroughly enough, the results are going to be disappointing."
In response to criticism about the company, ShotSpotter sent a statement defending its technology and its effectiveness:
"The ShotSpotter system is highly accurate, with a 97% aggregate accuracy rate for real-time detections across all police department customers as independently verified by data analytics firm Edgeworth Analytics. We are trusted by police departments in over 135 cities nationwide and have a 99% customer retention rate, indicating that our system works well and is a proven tool that saves lives and helps law enforcement respond to gunfire incidents with a fast, precise police response to gunfire in cities nationwide."
The below statement addresses misclassifying sounds:
"Furthermore, our computer algorithm helps us filter out sounds that aren't gunfire so there isn't a police response to non-gunshot sounds. Sounds that are not filtered out are analyzed by human reviewers in the Incident Review Center who have been extensively trained to distinguish the sounds of gunfire from other sounds, like fireworks or cars backfiring, and if the sound is gunfire, they publish an alert to law enforcement."