Last month, the day after a gunman opened fire on a crowded Brooklyn subway, New York City Mayor Eric Adams went on Good Morning America to talk about his plans for improving transit security. His big idea, which he had first floated in January, involved installing artificial intelligence-driven weapons detectors in the subway system.
“Technology has advanced so much,” Adams said. “There’s a new method that can detect weapons that are not the traditional metal detectors that you see at airports. You don’t even realize it’s there.”
But the technology Adams was talking about, which has never been implemented at scale on public transit, has issues that could present major problems for New York’s more than 3 million daily pandemic-era subway passengers. The detectors can be inaccurate, misidentifying an array of everyday objects, from cell phones to umbrellas, as threats. When those detectors ping an item, the person carrying it must be routed to more conventional secondary screening, which could cause significant delays for riders.
Even some companies that sell the technology that Adams is proposing — which is currently deployed in schools, workplaces, hospitals, and ticketed venues across the country — aren’t sure that it’s ready for public transit. Speaking to security and surveillance tech research firm IPVM late last month, Peter Evans, CEO of Patriot One Technologies, which sells its covert walk-through weapons detectors to event venues and secure buildings, said it would “radically change” subway riders’ experience. “Expect delays, expect secondary screening, expect frustration and expect to miss your train from time to time,” he said.
Albert Fox Cahn, executive director of the Surveillance Technology Oversight Project, agreed. “If we actually tried to deploy this technology, it would be absolute chaos at the train stations,” he said. “They clearly aren’t ready for primetime.”
While the Adams administration is still working out the details of its official proposal for subway scanners, it has confirmed one vendor on its shortlist: Massachusetts-based Evolv Technology, whose products and business model illustrate the potential pitfalls of deploying weapons detectors in mass public transit systems. (Evolv is confident in its systems’ utility, with CEO Peter George telling The Wall Street Journal after the Brooklyn shooting that his company was “born to solve this exact problem.”)
Like its competitors’ products, Evolv’s systems involve walk-through full body scanners equipped with machine learning software programmed to distinguish guns, knives, and other “threat” objects from everyday items. In theory, there is no need to remove clothing or items from one’s bag or pockets before going through an Evolv smart body scanner, and security staff can screen people at a quick pace.
But Evolv’s own promotional materials indicate that the company’s products frequently issue false alerts, which the company has not disputed. The exact misidentification rate is unknown, as Evolv and its competitors tightly control their data. But a review of company brochures, which Evolv says show figures from a “demonstration account,” and testimony from a prospective customer suggest the scanners may misidentify objects so often that if Evolv’s scanners were installed throughout the New York subway system, hundreds of thousands or millions of riders might be flagged as threats each week.
The systems are also costly. An Evolv subscription costs between $2,000 and $3,000 per scanner per month. Adams has said that he would propose a small-scale pilot program; taking into account the trained staff required to operate each machine, it could cost hundreds of millions of dollars annually should the mayor decide to scale that up to cover each of the 1,928 entrances to New York City’s 472 subway stations.
The Adams administration has assured the public that it’s doing its due diligence in researching the weapons detection technology. “Mayor Adams has made clear that public safety is his top priority, and he is willing to test and analyze numerous forms of technology in a legal, responsible way to protect New Yorkers,” Adams’s press secretary, Fabien Levy, said in a statement to New York Focus and Fast Company.
But the state of the smart body scanning tech raises serious questions. As Patriot One’s Evans noted to IPVM, “weapons detection solutions are still in the early stages of their innovation cycles,” and trying them out in new venues “can be a logistical nightmare.”