The number of stop-and-frisk reports filed by the New York City police fell 51 percent in the first three months of 2013, compared with the same period last year, the Wall Street Journal reports. The decline comes as the crime-fighting tactic undergoes a high-profile challenge in the federal court.

From Jan. 1 through March 31, officers conducted 99,788 stop and frisks, compared with 203,500 during the same period in 2012. It was unclear how many of these encounters resulted in an actual frisk after a stop.

Generally, the number of officers assigned to Operation Impact (a program that assigns rookie officers to patrol high-crime areas) tends to have the greatest impact on the number of stops, WSJ reports. Figures release Friday show that the reduced stops in the first quarter resulted in a 43 percent decline in weapons recovered compared with the same period in 2012, and overall crime is down 2.7 percent this year. Murders are down 30 percent compared with the same period last year.