Fanning out along the platform at the City Hall subway station in Manhattan, the plainclothes police officers blended in with the morning commuters. As they prepared to board a northbound train, they watched closely, their eyes darting from rider to rider.
The team of seven officers was searching for men who use the subway’s crowded confines to get too close to women. Some furtively touch female passengers, while others rub up against the women they have targeted.
At Union Square, Detective Marquis Cross saw a man he recognized from a previous sex-offense arrest standing suspiciously close to a female passenger. As the woman left the train, Detective Cross jogged after her to ask if she had felt anything unusual. She said that she had not, but that the man did seem too close.
The officers, all from the New York Police Department’s Transit Bureau, were working the Lexington Avenue line, one of the most overcrowded in an increasingly crowded system. The ever-tightening crush of passengers provides easy cover for men who prey on women, the police say.
Offenders will often step off a car and get back on just before the doors close so they have to squeeze next to other riders, Detective Cross said. “They’re looking for a particular crowd or person that they want to get behind,” he said.
Opportunistic sex crimes aboard subways are not new, nor are they news to many women. Some have been grabbed or leered at by a man who is masturbating. Many others have heard a story from a friend who felt an uncomfortable touch but was unsure if she should say something.
But cellphone cameras and social media have given women tools to fight back and provided the police a way to identify some offenders. Last year, in an effort to encourage more victims to come forward, the police began training more female officers to work the cases.
The police now send out a stream of alerts about such crimes using photos from victims’ phones to try to identify suspects. One recent Twitter post shared a photo of a man suspected of grabbing a 27-year-old woman’s buttocks on a No. 7 train in Queens this month. Two days earlier, the police posted a photo of a man they say exposed himself to women on two trains at Grand Central Station.
Reported sex crimes on the subways rose 19 percent last year, to 738 from 620 in 2014. Many of those crimes were forcible touching and public lewdness, the offenses most commonly charged in connection with the sort of sexual misconduct that Detective Cross and his colleagues were on the lookout for that morning on the Lexington Avenue line.
Joseph Fox, the chief of the Transit Bureau, said he believed the increase in reported sex crimes was a result of more women coming forward. He expects the number of reports will keep rising as the police continue to talk about the problem.
“Many men don’t know this issue exists; far too many women do,” Chief Fox said in an interview. “It’s a crime that goes largely unreported.”
Subway announcements have long warned riders about sexual misconduct, and social media and pop culture have amplified attention to it. The phenomenon was a plotline on the Netflix series “Master of None” when Aziz Ansari’s character confronts an offender on the subway.
The police made about 400 arrests last year for sex offenses on the subways, nearly three-fourths of which took place when officers witnessed an episode or a victim sought out a nearby officer who located the suspect. Victims are often embarrassed, confused or rushing to work, so they may not stop to tell a transit worker or go to a police station, Chief Fox said.
One of two female officers on the recent patrol, Lt. Angela Morris has become well versed on sex crimes in the two and a half years she has worked on such cases. Victims are frequently crying and express shock and humiliation, and they often appear more comfortable speaking to her rather than to her male colleagues, she said.
“She’s more free to tell me everything that she felt happen to her,” Lieutenant Morris said, adding that she had taken women whose clothing was damaged to buy a new outfit.
The most common reports in 2015 were for forcible touching (340 cases) and public lewdness (223 cases), both misdemeanors. There were 130 episodes of sexual abuse, which can be a misdemeanor or a felony. Rapes, which are felonies, are rare on the subway, Chief Fox said. One was reported last year, and five were reported the previous year.
In 2014, the Metropolitan Transportation Authority created a website for sexual misconduct complaints, where riders can attach a photo or make an anonymous report. The agency has received more than 500 complaints so far, and it forwards them to the police, officials said.
In September, Tiffany D. Jackson, a 33-year-old fiction writer who lives in Crown Heights, Brooklyn, said that a man followed her onto a No. 3 train in Brooklyn, exposed himself and masturbated while staring at her. She told the train operator and filed a report at a police station, though it was only after she posted an explicit photo of the man on Instagram and it circulated online that he was arrested.
At the Brooklyn station where Ms. Jackson first reported the encounter, the train operator directed her upstairs to a station booth for assistance. But she did not find that booth, and then, Ms. Jackson saw the offender standing next to her.
She said she hopped the turnstile, raced down to the platform and jumped on the next train toward Manhattan. At Times Square, she went to a police station, where she said officers wrote down her information and a description from the photo on her phone.
But Ms. Jackson said it felt as though they did not take her seriously. After she posted the photo on Instagram and her story spread, Chief Fox emailed her to say that he was sorry she had been victimized on the subway and that he took such cases seriously.
“What’s so disturbing is that if I hadn’t posted the picture, one: He wouldn’t have been caught,” Ms. Jackson said. “And two: Nothing would have happened.”
As part of training for transit officers assigned to sex crimes, an anti-harassment group called Hollaback is providing guidance. The group’s deputy director, Debjani Roy, said officers must not dismiss victims’ concerns.
“It’s important to build that empathy and understanding that it is a very traumatic experience,” she said.