How the N.Y.P.D.’s Facial Recognition Tool Landed the Wrong Man in Jail

New York|How the N.Y.P.D.’s Facial Recognition Tool Landed the Wrong Man in Jail

In February, a woman told the police that a delivery man had exposed himself to her in a Manhattan building. He was about 5 feet 6 inches tall.

Two months later, evidence shows, the police arrested the wrong man. He was 6-foot-2.

The man, Trevis Williams, was driving from Connecticut to Brooklyn on the day of the crime, and location data from his phone put him about 12 miles away at the time. But a facial recognition program plucked his image from an array of mug shots and the woman identified him as the flasher.

Like Mr. Williams, the culprit was Black, had a thick beard and mustache, and wore his hair in braids. Physically, the two men had little else in common. Mr. Williams was not only taller, he also weighed 230 pounds. The victim said the delivery man appeared to weigh about 160 pounds. But Mr. Williams still spent more than two days in jail in April.

“In the blink of an eye, your whole life could change,” Mr. Williams said.

The algorithms that run facial recognition technology can outstrip fallible human eyewitnesses, and law enforcement agencies say the results are not decisive on their own. But the case against Mr. Williams, which was dismissed in July, illustrates the perils of a powerful investigative tool that can lead detectives far astray.

Researchers at the National Institute of Standards and Technology have found in repeated testing that facial recognition technology identifies the correct person a vast majority of the time. But that research typically involved images taken under controlled conditions, not the grainy, blurry images of surveillance footage.

Nationwide, at least 10 people have been wrongly arrested after being identified with facial recognition technology, according to news reports. “We’ve seen this over and over across the country,” said Nathan Wessler of the American Civil Liberties Union. “One of the primary dangers of this technology is that it often gets it wrong.”