Chicago police Capt. Steven Sesso operates a ShotSpotter gunshot-detection system in the Harrison District. | Frank Main/Sun-Times file
More than 40,000 ShotSpotter alerts prompted no formal reports of any crime over a 21-month stretch — amounting to an average of 61 unfounded deployments each day.
An analysis of the city’s gunshot detection system released Monday found that nearly 86% of police deployments to alerts of gunfire prompted no formal reports of any crime.
The research, conducted by the MacArthur Justice Center at the Northwestern University School of Law, shows there were more that 40,000 “dead-end deployments” to gunshot alerts recorded between July 2019 and mid-April — an average of 61 each day.
Just 10% of the alerts over that period sent officers on calls that likely involved guns, the researchers found after analyzing records kept by the city’s Office of Emergency Management and Communications.
ShotSpotter, the publicly traded company that provides its acoustic gunshot detection technology to Chicago and 110 other cities across the country, claims its system is a “vital tool for law enforcement” that’s 97% accurate.
But activists continue to raise concerns about ShotSpotter’s ability to distinguish between gunfire and other loud noises like fireworks. In addition, alarms are being sounded over the technology’s potential to increase the number of highly charged law enforcement interactions in police districts with large minority populations.
“It sends police racing into communities searching, often in vain, for gunfire,” said Jessey Neves, a spokesman for the MacArthur Justice Center. “Any resident in the area will be a target of police suspicion or worse. These volatile deployments can go wrong in an instant.”
Linda Druss, a spokeswoman for ShotSpotter, said the company hasn’t reviewed the findings of the new study. Still, Druss insisted that ShotSpotter enables cops to “render rapid assistance to gun violence victims [and] reduce violent crime, helping to bring peace to communities suffering from persistent gun violence.”
“ShotSpotter technology is incredibly accurate, alerting officers to the exact location of gunfire incidents in less than 60 seconds, finding victims who need assistance, getting them medical aid faster [and] saving lives,” Druss said.
The Chicago Police Department’s experiment with ShotSpotter began in 2012 when the technology was implemented to cover a small portion of the city. That reach expanded to over 100 square miles when the department entered into a new $33 million contract in 2018, at which point ShotSpotter described the city as its “largest customer.” The current contract is now set to expire in August.
Police spokesman Tom Ahern couldn’t say whether the department plans to continue using ShotSpotter, but he lauded the technology as an integral piece of the city’s crime-fighting toolkit. Both he and Druss claimed it gives officers an edge to respond to shootings that aren’t reported to 911 call centers.
“In order to reduce gun violence, knowing where it occurs is crucial,” said Ahern. “ShotSpotter has detected hundreds of shootings that would have otherwise gone unreported. The Chicago Police Department’s expansion of ShotSpotter is helping us reduce crime and make our neighborhoods safer.”
The Chicago Police Department’s use of the gunshot detection technology has drawn increased attention after the death of 13-year-old Adam Toledo, who was fatally shot by an officer responding to ShotSpotter alerts in late March. Freddy Martinez, executive director of the transparency nonprofit Lucy Parsons Labs, penned an op-ed last week in South Side Weekly calling for an end to the city’s relationship with ShotSpotter in the wake of his killing.
“We must work to abolish the use of surveillance technologies to bring justice for Adam Toledo and others like him,” Martinez wrote.
On Monday morning, Martinez’s group and two other nonprofits plan to file an amicus brief in a pending murder case in Cook County court that relies on ShotSpotter evidence. The MacArthur Justice Center is representing the organizations behind the filing, which draws on the new findings about ShotSpotter.
The defendant, 64-year-old Michael Williams, has pleaded not guilty to six counts of murder stemming from a fatal shooting on the South Side that happened amid a wave of looting late last May. Williams, who was denied bail, already filed a motion April 22 to exclude the ShotSpotter evidence, court records show.
Spokespeople for the Cook County state’s attorney’s office didn’t respond to an inquiry about the case. Officials in the Cook County public defender’s office, which is handling Williams’ defense, declined to immediately comment.
Monday’s filing piggybacks on Williams’ motion and urges the court to scrutinize ShotSpotter’s reliability given that the technology has “far-reaching consequences beyond this single case.” They note that other cities have dropped ShotSpotter “because the system sent their officers out on too many wild goose chases.”
Citing the technology’s “significant, cross-cutting consequences for the legal rights of Chicagoans” and the lack of any “meaningful judicial scrutiny” in Illinois, the groups asked the court “to take seriously its duty to investigate and ascertain the reliability of reports of gunfire that ShotSpotter generates.”