Cambridge police officers are pushing back on the City Council’s vote to stop using the gunfire detection technology known as ShotSpotter.
The Cambridge Police Patrol Officers Association, representing about 200 police, criticized last week’s decision to abandon a technology that listens for sounds of gunfire and alerts local law enforcement. ShotSpotter is used by more than a dozen municipal police departments in Massachusetts.
“This decision threatens to make Cambridge less safe by slowing emergency response to gunfire,” the union wrote in an emailed statement. “ShotSpotter has been part of Cambridge’s public safety infrastructure since 2014. Removing it now sets the city back more than a decade by eliminating a tool that alerts police to likely gunfire within seconds — including incidents when no 911 call is made.”
The decision comes just weeks after a shooting on Memorial Drive. The split vote, 5-2 with two abstaining, highlighted national concerns about gun violence and the implications of government surveillance. Councilors who voted to end the contract said it raised privacy concerns and data being potentially accessed by federal law enforcement. But those who voted to keep it argued the technology was an effective tool in helping police respond quickly to emergencies.
Cambridge’s council split in their vote last week to end the city’s use of ShotSpotter within the next 90 days, going against recommendations from the city manager and acting police commissioner to retain the surveillance capabilities. Federal grant funding from the Urban Area Security Initiative covers Cambridge’s $50,000 annual cost for ShotSpotter.
Kade Crockford, director of the Technology for Liberty Program at the ACLU of Massachusetts, told GBH News Tuesday that gunfire detection systems deployed in American cities have high rates of misidentifying sounds as firearms-related.
“ShotSpotter is not an effective tool. It produces error rates that are astonishingly high,” they said. “There are studies, including one conducted by my office here in Boston, using data from the Boston Police department that showed that about 70% of the time when officers in Boston were dispatched to respond to an alert from a gunshot detection system, they did not find any evidence of gunfire.”
Crockford urged cities to spend funds on proven gun violence-prevention programming, such as youth employment and supports for prison reentry.
Two Cambridge city councilors, who voted to keep ShotSpotter, criticized their board’s action in a Boston Globe opinion essay, saying it was based on fear and ideology and “rejected a tool that could help save lives.”
Councilors Tim Flaherty and E. Denise Simmons wrote that ShotSpotter is meant to address gunfire that residents are too afraid to report.
“People may stay silent out of fear, confusion, or mistrust,” they wrote. “In recent years, shootings and gun-related incidents involving youth from Cambridge and neighboring Somerville have shaken neighborhoods and raised serious questions about response time. Even if no one is killed, the damage is real: families frightened, streets disrupted, and residents left wondering whether help will arrive in time.”
An April presentation from the Cambridge Police Department found that, since 2015, there were 11 shootings that were picked up by ShotSpotter but not reported to 911.
SoundThinking, the company that runs the ShotSpotter technology, said in a statement that it is reviewing the implications of the City Council’s vote.
“SoundThinking is proud to have successfully served the Cambridge Police Department and the citizens of Cambridge with gunshot detection services since 2014,” a spokesperson for the company said in an email to GBH News. “ShotSpotter is proven, unbiased technology that detects and alerts police to gunfire, enabling faster response, evidence collection, and lifesaving medical aid all the while preserving privacy. We remain committed to working with communities, like Cambridge, that share our belief that every resident deserves those protections against gun violence.”
Dozens of Cambridge residents spoke at the meeting, telling councilors that the technology unfairly targets neighborhoods in the city with higher concentrations of Black and Latino residents and expressing concerns that the audio sensors can record people’s conversations.
“Stop wiretapping Cambridge,” one resident said.
Councilor Ayah Al-Zubi agreed with opponents of the technology, sharing her concerns about privacy intrusions and questioning its reliability.
“The benefit does not outweigh the risks of situations where our police department might be misled,” she said.
Councilor Jivan Sobrinho-Wheeler said ShotSpotter was making his city less safe.
“We know that it misses many of the actual gunshots, and it’s dangerously inaccurate,” he said. “It sends police into communities of color where there are no gunshots, where there are firecrackers or other loud noises.”
Sobrinho-Wheeler also said that he valued community input as the council debated whether to continue using the gunfire detection system.
“We never did that for [ShotSpotter],” he said. “There was never a chance for the community to weigh in [in 2014]. It was just deployed.”
