The number of guns recovered from crime scenes in New York City has dropped dramatically in the past year, new numbers disclosed by the Bureau of Alcohol, Tobacco, and Firearms show.

The New York City police department turned over 5,913 guns recovered from crime scenes to the ATF last year, down from 7,059 in 2006. Besides the spike in 2006, the numbers have fluctuated only slightly in the past few years, with ATF and police representatives attributing the recent drop to law enforcement efforts to crack down on firearms trafficking.

On a visit to the city this week, the acting director of the ATF, Michael Sullivan, hailed the reduction in guns recovered last year as a sign that illegal guns are becoming harder to obtain.

“We hope that means there are fewer weapons ending up in the hands of criminals,” Mr. Sullivan said of the report released yesterday.

A spokesman for the New York City Police Department, Deputy Commissioner Paul Browne, noted that the drop in guns had corresponded with a year in which murder numbers reached record lows. “Enforcement generally and Operation Impact, which targets areas where shootings have spiked, appear to have had a deterrent effect,” he said.

A vast majority of the guns recovered last year in crimes that were traceable, 87%, led back to gun sellers in other states, the ATF reported. That’s a slight uptick from 2006, when 85% of traceable guns came from out of state.

ATF agents brought down one gun trafficker last fall whom they eventually linked to more than a dozen illegal out-of-state guns, the officials said. In that instance, the agents tracked a gun found on a New York City homicide victim back to a seller in Queen City, Texas, who had sold the gun only a few months before the shooting. The agents were then able to find and arrest an alleged straw purchaser, Aaron Underwood, who allegedly bought guns for an alleged trafficker, along with the alleged trafficker, David Parker. They said that they are seeking a third person involved in the ring.

Still, ATF officials said that one of the main indicators of rampant firearms trafficking — a short time period between the purchase of the gun and its use in a crime — was mostly absent in New York City. Here, the time-to-crime, as it is called, has been gradually lengthening. In 2001, the average crime gun was used 11.5 years after it was originally purchased. In 2006, the length of time rose to 12 years, and in 2007, the time-to-crime was 13 years.