New York City will soon start testing out technology that uses AI to detect guns at subway turnstiles, Mayor Eric Adams said on Thursday. Adams’ announcement comes one week after an altercation at a subway station in Brooklyn in which a man was shot with his own gun after pulling it on another passenger.

Adams said the city is partnering with Evolv, a Massachusetts-based weapons detection company whose detectors are used in schools and venues across the country. Evolv, however, has faced scrutiny over the accuracy of its machines, as well as two government probes and a class action lawsuit by shareholders.

The pilot will start in 90 days, in accordance with the POST Act, which requires the New York City Police Department to disclose the surveillance technologies it uses and publish impact and use statements before new technologies are put into place. Adams said the city will also use the 90-day waiting period to vet other vendors. “This city has a technology mayor,” Adams said. “Bring us your technologies. Let us test it.”

Adams did not say where the scanners will be installed or how many will be in use. Evolv scanners are already in use at Citi Field — Evolv is the “official fan screening provider of the Mets” — Lincoln Center, and the Metropolitan Museum of Art. Adams temporarily installed an Evolv scanner outside the entrance to City Hall in 2022 after a shooter opened fire on a subway car in Brooklyn. That year, the city ran a similar Evolv pilot at a hospital in the Bronx after a man was shot inside the ER waiting room there. Dozens of school districts across the country have also installed Evolv scanners in attempts to prevent campus shootings.

Evolv’s scanners look like metal detectors but are equipped with AI. The company claims the scanners use “safe, ultra-low frequency, electromagnetic fields and advanced sensors to detect concealed weapons.” Evolv CEO Peter George has claimed the scanners can detect virtually any type of weapon. “We’ve written the signatures for all the threats that are out there: all the guns that exist, all the bombs, all the large tactical knives,” George said in 2021. 

But reports suggest the technology doesn’t actually work all that well. Evolv’s scanners have reportedly flagged umbrellas as guns but failed to detect aluminum and steel tubes that were cut to look like gun barrels. Last year, The Intercept reported that some school districts were frustrated by Evolv’s machines failing to detect knives in students’ backpacks or mistakenly identifying lunchboxes as bombs.

In 2022, the surveillance industry research publication IPVM reported that Evolv had paid for testing by the National Center for Spectator Sports Safety and Security, which the company later described as “fully independent.” Evolv also edited the purportedly independent report, removing information about the low rates of detection for certain weapons, according to the IPVM report.

Last October, the Federal Trade Commission opened an inquiry into whether Evolv’s AI detection system works as advertised, and in February, Evolv disclosed that the Securities and Exchange Commission had also opened a “non-public, fact-finding inquiry.” In March, investors filed a class action lawsuit alleging that the company had misrepresented the efficacy of its products and “deceived the general public, customers, and investors.”

Evolv nonetheless remains Adams’ preferred vendor. Some of the mayor’s top donors hold sizable investments in Evolv, the New York Daily News reported in 2022. “Imagine me saying, ‘No, we’re not going to invest in technology that can identify guns because someone is an investor in that technology,’” Adams said in 2022. “You know, good technology saves lives. I have an obligation and a responsibility to bring it forward.”

The pilot has already drawn critics. “Gun detection systems are flawed and frequently trigger false alarms,” the Legal Aid Society, the city’s largest public defender nonprofit, said in a statement. “Contrary to the mayor’s claims, New York City should not serve as a testing ground for surveillance corporations; the public has not consented to be a part of these experiments.”

Adams noted that violent crime on the subway system, gun-related or otherwise, remains relatively rare. Crime is down city-wide, with a 16 percent decrease from February to March, Adams said — but polls suggest that New Yorkers feel increasingly unsafe anyway. “If they don’t feel safe, then we aren’t accomplishing our task,” Adams said. “Stats don’t matter if people don’t believe they’re in a safe environment.”