Hidden Link

May 15, 2024

By MICHAEL JONAS

Gunshots ring out in a densely populated city neighborhood. WIthin seconds, based on data from an array of sound sensors deployed in the area, police are able to pinpoint the exact spot where the gunfire happened and dispatch the nearest officers to the scene, giving them a leg up in the race to catch the shooter and help any victims. 

It’s hard to imagine why anyone would oppose having that kind of technological aid in the public-safety toolkit. But the evidence supporting gun detection technology, which has landed in scores of US cities, is not nearly that clear-cut, with the most comprehensive study to date suggesting it confers no public safety benefit.

Across the country, critics are raising questions about the impact of the high-tech gunfire locators on the heavily minority communities where they tend to be sited, asking whether they actually make those neighborhoods safer or just subject residents to more surveillance. The debate landed in Boston on Monday, where Police Commissioner Michael Cox faced tough questions at a City Council budget hearing about the city’s use of ShotSpotter, the brand name of the gun detection system the city has used since 2007. 

Cox told councilors the technology is “how we stay safe” and said it’s crucial to how officers are deployed in some areas. 

The accuracy of ShotSpotter is subject to wildly disparate claims. 

SoundThinking, the California company that owns ShotSpotter, says the sensors have a 97 percent accuracy rate, and says the technology “saves lives in the places hit hardest by gunfire.” 

But a report released last month by the ACLU of Massachusetts, based on an analysis of Boston ShotSpotter records from 2020 to 2022, said that in almost 70 percent of ShotSpotter notifications there was no evidence of gunfire.

As a result, said Kade Crockford, director of the organization’s Technology for Liberty Program, officers are often on “a wild goose chase,” looking for something that isn’t there. Because the sensors are concentrated in Boston’s predominantly Black and Hispanic communities, where gun violence is concentrated, Crockford said it is overwhelmingly minority residents who end up getting questioned and facing unwarranted scrutiny from police responding to false alerts. 

Eric Piza, a professor of criminology and criminal justice at Northeastern University, has led the most sweeping investigation of the technology to date, a recently completed study of 15 years of ShotSpotter data from Kansas City and Chicago. 

Piza said the study found that police got ShotSpotter alerts, on average, about 90 seconds earlier than 911 calls, and the technology led to police locating more ballistic evidence at shooting scenes.

“However, we found that none of that translates to any meaningful public safety benefit,” he said in an interview. “Gun violence did not decrease. Shootings were not any more likely to be solved after the introduction of ShotSpotter.” He said there was also no evidence that ShotSpotter reduced gunshot fatalities through faster emergency response, as SoundThinking claims. 

In February, Mayor Brandon Johnson announced that Chicago would end its use of ShotSpotter. Piza presented his results to city officials several weeks before the announcement. 

On Monday, Sens. Ed Markey and Elizabeth Warren, as well as Rep. Ayanna Pressely, sent a letter to the inspector general at the Department of Homeland Security asking the office to investigate the department’s grant funding of ShotSpotter systems. The lawmakers cited potential federal civil rights violations related to over-policing of minority neighborhoods as result of ShotSpotter’s high error rate. 

City Councilor Henry Santana has filed an order to hold an oversight hearing specifically focused on ShotSpotter, but Cox didn’t seem interested in further discussion, telling city councilors on Monday that he plans to renew the department’s contract for the system when it expires next month. “The fact is, it saves lives,” Cox told councilors. 

Piza said the idea that there would be strong benefits from a high-tech policing tool like ShotSpotter makes some sense intuitively, but the evidence just isn’t supporting that hunch. 

“Technology and public safety can be tricky,” he said.