US Justice Department Urged to Investigate Gunshot Detector Purchases

The United States Justice Department (DOJ) is being asked to investigate whether a gunshot-detection system widely in use across the US is being selectively deployed to justify the over-policing of mainly Black neighborhoods, as critics of the technology claim.

Attorneys for the nonprofit Electronic Privacy Information Center—a leading US-based civil liberties group—argue that “substantial evidence” suggests American cities are disproportionately deploying an acoustic tool known as ShotSpotter in majority-minority neighborhoods. Citing past studies, EPIC alleges that data derived from these sensors has encouraged some police departments to spend more and more time patrolling areas where the fewest number of white residents live—an allegation disputed by SoundThinking, the system’s manufacturer.

In a letter today to Merrick Garland, the US attorney general, attorneys for EPIC call for an investigation into whether cities using ShotSpotter are running afoul of the Civil Rights Act—namely, Title VI, which forbids racial discrimination by anyone who receives federal funds.

“State and local police departments around the country have used federal financial assistance to facilitate the purchase of a slew of surveillance and automated decision-making technologies, including ShotSpotter,” EPIC says. Despite mounting evidence of ShotSpotter’s discriminatory impact, there is no indication that its Title VI compliance has ever been seriously assessed. 

“We are aware of the letter and believe it has no merit," a SoundThinking spokesperson tells WIRED in a statement. "Ensuring that ShotSpotter technology provides safe and equitable response efforts to communities is something SoundThinking takes extremely seriously.”

ShotSpotter has been deployed in more than 150 cities in the US, according to the company. It relies on internet-connected acoustic sensors, often attached to utility poles, and aims to detect gunfire using machine algorithms. SoundThinking says “acoustic experts” are on staff around the clock to review alerts and “ensure and confirm that the events are indeed gunfire.” The company claims its sensors have a 97 percent accuracy rate, disputing reports that alerts triggered by fireworks and other high-impact sounds affect the system’s accuracy.

EPIC is urging the DOJ to consider research that suggests ShotSpotter has produced “tens of thousands of false alerts” while simultaneously being deployed “in predominantly Black neighborhoods.” One such study, launched by the city of Chicago’s inspector general in 2021, noted that the “frequency of ShotSpotter alerts in a given area may be substantively changing policing behavior.” The agency concluded that, despite the city’s investment of $23-33 million, ShotSpotter alerts “rarely produce evidence of a gun-related crime, rarely give rise to investigatory stops, and even less frequently lead to the recovery of gun crime-related evidence during an investigatory stop.”

News investigations in Ohio and Texas have similarly raised doubts about the system's effectiveness, revealing that in some cases its alerts have delayed responses to 911 calls. Working to expand the use of ShotSpotter in Houston in late 2020, the city also green-lit a pilot program that saw sensors deployed across two areas where communities are between 80 and 95 percent people of color.

EPIC is pressing Garland to investigate whether local law enforcement agencies have used federal grant money to buy ShotSpotter, and if so, ascertain whether those grants conformed with Title VI. Moreover, EPIC is seeking new guidelines for funding systems designed to automate police work: rules to ensure such arrangements are “transparent, accountable, and nondiscriminatory.” The attorney general should take additional steps, EPIC says, to ensure agencies dispersing federal funds are careful to assess whether tech companies meet “minimum standards of nondiscrimination” and that new police technologies are not only justified but necessary to achieve a “defined goal.”

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