What's behind the recent spike in NYC shootings?

NEW YORK - A recent spike in shootings in New York City has some officials pointing to the decline in the use of the NYPD's controversial "stop and frisk" practice, but experts are urging caution in linking fewer stops to more crime.

While year-to-year crime in the city is down, there's been an uptick in shootings in some neighborhoods in recent weeks. Last weekend, a wave of violence in all five boroughs left at least 21 shot, reports CBS New York. Four of the shootings were fatal.

The victims included a 10-year-old boy who was shot in the knee in Brooklyn's Coney Island Saturday, reports the station. A 12-year-old boy was also shot and wounded in the Bronx on Sunday.

Gunfire erupted again on Monday, when a gunman demanding a job entered an iron business in Brooklyn's Gowanus neighborhood, shooting and injuring two and fatally shooting himself after a standoff.

"We've had an increase, a temporary increase, in shootings," Police Commissioner William Bratton said, reports the AP. "Crime goes up, it goes down."

Bratton announced last week that his department will study years of data to determine whether the drop in "stop and frisks" -- a practice in which police can stop and question someone if they suspect criminal activity may be underway - could be impacting crime in the city.

The tactic was championed by former police commissioner Ray Kelly and former mayor Michael Bloomberg as a key crime-fighting tool, but critics said police overused the practice, often times without adequate suspicion and in a racially discriminatory manner.

Last August, a federal judge agreed, ruling in favor of plaintiffs who sued the city that the NYPD was unconstitutionally using stop and frisk to target minorities. The judge's ruling called for a monitor to oversee changes.

Campaigning on a promise to reform the practice, New York Mayor Bill de Blasio sought to drop the city's appeal of the ruling after taking office in January, and the case was sent to a lower court to hammer out details of the reforms. De Blasio and Bratton have said the practice caused New Yorkers to be wary of police and lowered morale for officers who have reduced crime to record lows, reported CBS New York.

Stop and frisk surged in the city under Kelly and Bloomberg, from fewer than 100,000 stops in 2002 to more than 685,000 stops in 2011, but the practice has since dropped dramatically, with under 200,000 stops in 2013, according to data provided by the New York Civil Liberties Union.

So could there be a link in the drop in stops and the recent spike in shootings?

"Potentially, sure, but you have to use caution in looking at a particular weekend or set of weekends in declaring the sky is falling," said Eugene O'Donnell, a former New York City police officer and professor of law and police studies at John Jay College.

It can be difficult to pinpoint the cause of short-term spikes in crime, O'Donnell said, and it's not uncommon for weekends in the summer to be marked by violence in New York.

However, O'Donnell said that people who carry guns are often the first to be aware of changes in police tactics, and the publicity surrounding the drop in stops may have emboldened some criminals.

"There is a risk in a perception that the police have stood down in communities where gun violence is a big issue," he said.

Last weekend marked the third weekend in June that at least a dozen people were shot in the city, according to police. In the last week of June, 35 people were shot, down from 39 gunshot victims the same week a year ago, according to New York Police Department statistics. A breakdown between those killed and those wounded was not immediately available.

This year, 611 people have been shot in the city compared with 554 for the same period last year.

"Looking at short-term comparisons is difficult," Bratton said at a press conference Friday. "You look over--trending--over time."

Some local officials, including New York City Councilman Eric Ulrich, say the link between the short-term increase in shootings and fewer stops is crystal clear. In a statement, Ulrich said the recent shootings "contradict two decades of crime reduction in our city and make the strongest case for bringing back stop, question and frisk."

But critics of the practice, including the New York Civil Liberties Union, say there's no evidence the stops make the city safer - and they say data backs their claim.

As stops dramatically increased between 2002 and 2011, there wasn't a significant change in the number of shootings, according to police data they provided - 1,892 in 2002 and 1,821 in 2011.

"There's no real relationship between stop and frisk and shootings," said Chris Dunn, NYCLU associate legal director. "There's spikes in criminal activity all the time, and when you look at 12 years of data, the lack of relationship is quite clear."

One New York City councilman is calling on the media to stop drawing the comparison. Brooklyn Councilman Jumaane Williams, who has pushed for anti-stop-and-frisk measures, said at a press conference Tuesday the tactic isn't effective and unfairly burdens communities of color, reports the Brooklyn Observer.

"There is no correlation between the amount of stops and the number of shootings," Williams said, reports the paper. "I ask you to stop trying to connect those dots."

In preparation for summer crime, Bratton said last week an additional 1,200 officers will be headed to New York City's streets this week in areas marked by a spike in shootings.

Using stop and frisk in situations where reasonable suspicion does exist - and following up on violent incidents to catch shooters before they shoot again - are key tactics to making the city safer, said John Jay's O'Donnell.

But even ahead of his department's completion of the study on the impact of the drop in stops, Bratton said he didn't expect to see a link to the shooting spike.

"Being quite frank with you, my speculation is even before the study comes back--I'd be very surprised if we're going to show any direct correlation between the decline of stop, question and frisk and the short-term increase in shootings," Bratton said.