The use of stop-and-frisk in New York exploded under former Mayor Michael Bloomberg, rising from under 100,000 encounters in 2001, the year before he took office, to more than 685,000 in 2011. That year, 87 percent of those stopped were black or Hispanic, groups that make up only about half of the city's population. Crime did drop in New York during that period, but not as much as it did in other cities, like Los Angeles, that did not engage in the practice. The Center for Constitutional Rights, which brought the stop-and-frisk lawsuit, responded today to Mr. Trump's claims and noted that police reported about 106,000 major felonies in New York in 2011. In 2015, the last year for which statistics are available, police conducted just 23,000 stops, yet major felonies were slightly down, to about 105,000. The city saw 515 murders in 2011 but just 356 in 2015.