NEW YORK — Donald Trump says the police tactic known as stop-and-frisk led to a drop in murders in New York City, while Hillary Clinton says it has been ruled unconstitutional.

At the first presidential debate, neither was quite right.

The New York Police Department’s use of stop-and-frisk, an approach to policing in which officers can stop and search anyone they deem suspicious, emerged as a flashpoint Monday night for the two New Yorkers.

Trump painted a dark picture of violence in the United States’ inner cities and suggested the solution would be “you do stop-and-frisk,” adding it “worked very well” in the nation’s largest city.

“In New York City, we had 2,200 murders, and stop-and-frisk brought it down to 500 murders,” Trump said, praising former Mayor Rudy Giuliani for his embrace of the tactic. The Republican nominee said it was “continued on by Mayor (Michael) Bloomberg. And it was terminated by current mayor. But stop-and-frisk had a tremendous impact on the safety of New York City. Tremendous beyond belief.”

Murders have plunged in New York, and the drop did begin under Giuliani in the 1990s, with the number of homicides falling to fewer than 600 a year by 2002. But while the tactic officially known as stop-question-and-frisk was part of the strategy used by the NYPD in the 1990s, it didn’t become a major police tool until the next decade.

The peak use of stop-and-frisk, under Bloomberg and his police commissioner, Raymond Kelly, was in 2011. That year, police made around 685,000 stops and there were 515 murders and 106,000 felonies committed in the city.

Trump also claimed that, after the use of stop-and-frisk was dramatically curbed, “murders are up. All right. You check it.”

He’s half right.

The number of stops has fallen nearly 97 percent since 2011, according to NYPD statistics. But the number of murders has fallen since then, too.

Bill de Blasio was elected mayor in 2013 on a promise to rein in the use of stop-and-frisk, and murders in New York fell to a record-low 333 in 2014, his first year in office.

The number of homicides ticked up to 352 last year, but has dropped so far in 2016. As of Sept. 18, there have been 246 homicides in New York, down from 257 at the same time last year.

Trump “literally does not understand what he’s talking about,” de Blasio, a Democrat, said recently. “He’s either ignorant of the history of the city or he’s lying about it.”

De Blasio is among the critics of the tactic who say it disproportionately targeted black and Latino men. Clinton and debate moderator Lester Holt said Monday the practice itself has been ruled unconstitutional.

“Stop-and-frisk was found to be unconstitutional and, in part, because it was ineffective,” Clinton said. “It did not do what it needed to do.”

In 2013, U.S. District Court Judge Shira Scheindlin ruled stop-and-frisk violated the rights of minorities and its implementation in New York was unconstitutional, because the police were making stops due to race and not because they held a reasonable suspicion of wrongdoing. She ordered a federal monitor to oversee broad reforms of the police department.

But the tactic itself remains legal. Giuliani, a top Trump ally, said there’s “absolutely no question it’s constitutional.”

“It is still good law, as us lawyers say,” Giuliani said. “And it is being done right this very minute in just about every part of the United States.”

The tactic is still used in New York, but at a dramatically reduced rate: In 2015, there were 23,000 stops.

Trump was also largely right when he asserted the case “was taken away” from the judge who made the initial ruling on its use in New York.

The Court of Appeals for the Second Circuit criticized Judge Scheindlin, saying she “ran afoul” of the judiciary code of conduct by giving the appearance of bias and maneuvering to hear the lawsuit. The appeal court removed her from the case and granted a stay of her ruling.

But in 2014, de Blasio announced that he was dropping the city’s appeal of her initial ruling and would agree to her recommended reforms.

Associated Press writers Jill Colvin and Tom Hays contributed to this report from New York.

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