NYPD Commissioner William Bratton will speak publicly Monday about the latest downward crime trends in the city at a time when shootings continue to increase.

A persistent uptick in shootings has been one of the few troublesome crime trends facing Bratton since he took over as commissioner in January 2014. Police data show that shootings have increased around 17 percent so far this year over the same period last year, when the city reported an overall 6.3 percent increase in shootings.

Bratton has insisted the shootings are unrelated to the large drop in stop and frisk activity by cops. But the latest police data showed the New York City police precincts with the largest increases in shootings last year -- as well as, in a few cases, more homicides -- also reported having the lowest numbers of stop and frisks in 2014.

Last year's increase in shootings appeared to hit mainly precincts in the Bronx and Brooklyn, which also saw very little stop and frisk activity. Shootings ranged from rises of almost 9 percent in the 77th Precinct in Crown Heights to nearly 112 percent in the 69th Precinct in Canarsie, according to year-end NYPD data. The 77th Precinct reported only 135 stops last year while the 69th Precinct had 83, records show.

Citing a department study, Bratton has said that he doesn't believe the large drop in stop and frisk activity -- from nearly 700,000 in 2011 to about 47,000 in 2014 -- had any impact on the shooting increase last year. But Bratton's office has yet to release the study despite repeated requests. NYPD spokesman Stephen Davis declined to comment over the weekend about the trends.

Some criminologists studying the issue note, however, that there is at least some correlation between stop and frisk activity and serious crimes, including shootings. But they acknowledge the exact connection is hard to figure out.

"Where you find an increase in stop, question and frisk, at least when it was going, you do find small crimes decrease, but relatively small," said Professor Richard Rosenfeld of the University of Missouri-St. Louis, who with Professor David Weisburd of George Mason University, has studied the connections. Both released studies last year showing modest correlations between crime and stop and frisks. They are expected to release an updated study shortly.

But in an interview, Rosenfeld said using police precinct statistics, which cover a population area of about 110,00, makes it difficult to assess what other factors may be impacting shooting levels. He studied much smaller census tracts of about 5,000 people.

"The problem is that there could be a million things affecting the numbers here," Weisburd said in an email.

Weisburd said he prefers to use data from smaller high-crime intersections or street areas of the city.

"It does not mean that it isn't interesting," Weisburd said, referring to the 2014 shooting data, "But it is very hard to figure out."

In a recent law review article, Professor Jeffrey Bellin of William and Mary Law School stated that stop and frisk "only deters gun carrying if stops are seen as largely unavoidable" by criminals who carry guns.

But the problem is that such a high level of stop and frisks would be needed for that deterrent effect that the program would be practiced unconstitutionally by targeting certain demographic groups, as a federal judge found in 2013, said Bellin.