NEW YORK — Justin Serrano was 13 the first time he was stopped by police. He says he was walking his 7-year-old brother home from school when police forced him against a wall, patted him down and kept him in the back of a patrol car for more than an hour while both boys cried. Then they let Serrano go, telling him it was a case of mistaken identity. It was a pivotal moment in Serrano's life. Five years later, he sat with other Hispanic and black teenagers with similar stories at Make the Road, a community organization in a Brooklyn neighborhood of taco trucks, coconut ice cream vendors, and Puerto Rican flags peeking from grimy windows. Guided by two university professors, the teenagers were contributing questions for a survey on the New York City Police Department's “stop-and-frisk” tactic. The NYPD's policy of detaining and sometimes searching anyone officers deemed suspicious has prompted an emotional debate and a federal lawsuit. Opponents argue the strategy is unconstitutional and encourages racial profiling, while the city and its supporters say the stops have contributed to a dramatic drop in violent crime. The NYPD stopped close to 700,000 people on the street last year, up from more than 90,000 a decade ago. Nearly 87 percent were black or Hispanic. About half were frisked. About 10 percent were arrested. A federal judge in May granted class-action status to the lawsuit, meaning thousands of people who have been stopped over the years could potentially join the complaint introduced by the Center for Constitutional Rights on behalf of four black men. In June, the New York Civil Liberties Union rolled out a “Stop and Frisk Watch” smartphone app that allows bystanders to record police stops and instantly alert others to where it is taking place. US District Judge Shira Scheindlin said there was “overwhelming evidence” police have conducted thousands of unlawful stops based on flimsy justification such as “furtive movement.” She berated the NYPD for displaying “a deeply troubling apathy toward New Yorkers' most fundamental constitutional rights.” The next day, Police Commissioner Raymond Kelly announced changes to officer training and supervision, and the number of stops has since declined dramatically. But the commissioner and Mayor Michael Bloomberg fiercely defend aggressive policing they credit for transforming New York into one of the safest big cities in the US. They say the stop-and-frisk program has helped prevent thousands of deaths by taking guns off the street and deny allegations of racial profiling, saying more blacks and Hispanics are stopped because many minority areas have the highest crime rates. “Nobody should ask Ray Kelly to apologize — he's not going to and neither am I,” Bloomberg said on the day of the ruling. “And I think it's fair to say that stop, question and frisk has been an essential part of the NYPD's work.” Other cities have adopted policies systems similar to New York's, provoking the same debate. Last year, officials in Philadelphia placed its “stop and frisk” program under court supervision to settle a federal lawsuit alleging racial profiling. San Francisco Mayor Ed Lee faced a backlash when he raised the possibility of adopting “stop and frisk” to get guns off the streets. Lee announced Tuesday that he was no longer considering it. In New York, the police department has seen its approval ratings soar as homicides rates plummet, from a high of 2,245 killings in 1990 to 515 last year. A poll in March found that 63 percent of New York City voters approve of how the country's largest police force is doing its job. But New Yorkers are nearly evenly divided about “stop and frisk” with 49 percent of voters disapproving and 46 percent saying yes. — AP