Protestors march against the use of ShotSpotter in July. | Anthony Vazquez/Sun-Times
The Chicago Police Department and company executives on Friday defended the gunshot detection technology amid complaints that it rarely leads to investigatory stops or evidence of gun crimes and can change the way police officers interact with residents.
The Chicago Police Department and ShotSpotter executives on Friday defended the gunshot detection technology amid complaints that it rarely leads to investigatory stops or evidence of gun crimes and can change the way police officers interact with residents.
After repeated cancellations, the City Council’s Committee on Public Safety finally held an hours-long “subject matter” hearing on the much-maligned technology contract that the city chose to extend for two additional years at the request of CPD.
The acoustic gunshot detection system has come under heavy fire in recent months, with numerous studies and reports challenging its efficacy and accuracy. One of the most scathing of those reports was released in late August by the city’s own deputy inspector general for public safety.
The report analyzed more than 50,100 ShotSpotter notifications from last January through May. Just 9.1% indicated evidence of a gun-related offense was found. Only 2.1% of the alerts were linked directly to investigative stops, although other stops were detailed in reports that referenced the technology but didn’t correlate with a specific ShotSpotter notification.
But on Friday, CPD’s Deputy Chief Larry Snelling urged City Council members to view the glass as half-full, rather than half-empty.
“We can say that 85 [or] 90% of the time, the shot detection system doesn’t render any information. What we need to look at is the 10% of the time that it does,” Snelling told committee members.
“That 10% of the time could be the difference between the officers arriving on the scene applying a tourniquet … to stop a victim from bleeding out or getting an ambulance there a lot quicker to get these victims to the hospital.”
Just because there is no evidence of a gun-related crime when police officers arrive on the scene of a ShotSpotter alert does not mean that no crime occurred, Snelling said.
“In a drive-by shooting, people are shooting from vehicles. Which means that, if they use a semi-automatic weapon, when that weapon discharges, the shell casings are probably inside the vehicle that they’re shooting from,” Snelling said.
“If someone uses a revolver, you’re not going to find evidence of shell casings. Or, if they do it from an area where there is high traffic and traffic is moving through, that traffic can also destroy that evidence.”
Despite the independent studies questioning the technology, ShotSpotter has said that its own research shows it has an efficacy rate of more than 90% in the 12 police districts covered by the technology in the city.
Ralph Clark, president and CEO of ShotSpotter, said the company’s research also shows that more than 90% of gunfire in Chicago goes unreported.
“When a gun is fired and there’s no call to 911, we’re losing opportunities to collect evidence, deter and disrupt serial shooting cycles as well as showing the community that we care. And, most importantly, most importantly, we’re losing the opportunity to potentially save lives,” Clark said.
Clark noted that 79% of the shootings and 84% of the homicides in Chicago over the last 18 months took place in one of the dozen districts.
“Which tells us the city did a very good job of determining where ShotSpotter is needed the most and where ShotSpotter can provide the highest value,” he said.
Ald. Michele Smith (43rd) pressed ShotSpotter executives for “actual evidence” of the company’s claims about its efficacy rate.
Are police officers required to file reports when there is no evidence of either gunfire or fireworks?
“We would all like to know where a gun is coming from — especially in communities in which … nobody knows where the firing is coming from. They don’t want to call. But to say that it’s 97% accurate and it’s not based on anything other than sort of negative feedback is kind of like saying that customer satisfaction with my office is very, very high based on people not complaining,” Smith said.
“I’m very uncomfortable with that 97% claim. And quite frankly, I’m assuming it’s not accurate — by a lot.”
Ald. Carlos Ramirez-Rosa (35th) pressed ShotSpotter executives on whether or not they had tested to differentiate between gunshots and fireworks.
Clark responded that, for every 5,000 gunshot alerts in Chicago, ShotSpotter officials “listen to 100,000 bangs, booms and pops” — everything from fireworks and construction noise to car engines backfiring.
“If you had an opportunity to look at the variety of bangs, booms and pops that we’re filtering out of the process — we’re making sure it does not make its way to the officer in the field — you would come away with a lot more confidence in the performance we’ve established and how effective we are in dealing with fireworks and other things that can create that false-positive scenario,” the CEO said.
Ald. Jeanette Taylor (20th) was not appeased.
“For $9 million, you’re sending police to get a backfire off a truck on the expressway? Two-plus-two doesn’t equal four,” she said.
“I have a four-year-old that got killed in my ward. From ShotSpotter to cameras to Ring cameras and all this and we can’t solve no crime? … Officers are there after the crime. This is supposed to be something that helps us before. And it’s just not doing that.”