More than 2,000 alleged members of violent street gangs have been arrested in the city in just the last year and a half. Officials say the takedowns are a big reason New York is the safest it has been in more than 50 years.

The NYPD vows the arrests will continue. 

"What I am not going to have happen is woman walking down the street having to dodge bullets, kids growing up on a block that have to worry about two heroin dealers fighting over turf," said Dermot Shea, chief of crime control strategies for the NYPD.

The NYPD, along with federal law enforcement agencies and sometimes Homeland Security, have conducted 250 major operations against local gangs since April of last year. Twenty, thirty, forty, or more suspects arrested at one time. The sweeps taking place in every borough. 

In some cases, federal prosecutors are bringing charges. In the others, borough district attorneys. 

"Look, if there isn't a problem with gangs, if there isn't violence, if people aren't being shot at and killed, we have no interest," said Joon Kim, acting U.S. attorney for the southern district of New York.

Kim says gang activity is a lead cause of shootings in the city, an issue so important, he agreed to sit down with NY1 for his first one-on-one interview in his current role. He says a top priority for him is stomping out violent gangs.

"There are rival gangs that are doing, that are shooting at each other and maiming and killing each other, and there are innocent bystanders who are also who are being killed and being forced to live in areas where gun violence is a routine thing or where drugs are sold in the playgrounds. That's a big part of what our office's mission is," Kim said.

His office took part in the largest gang bust yet, 120 people charged in April 2016 with murder, shootings, drug dealing and other offenses, all from the Eastchester Gardens public housing complex and the surrounding north Bronx neighborhoods. All but eight have pleaded guilty.

The convictions were obtained under a 1970 law, the federal Racketeer Influenced and Corrupt Organizations Act, or RICO. It permits prosecution of gang members for being part of an enterprise that commits a series of crimes. 

"Gangs fall into that category, as do traditional Italian mafia or Asian gangs, all Russian gangs. And those allow you to charge all sorts of different crimes and then bring them all at the same time," Kim said.

The tactic of using RICO to go after street gangs is not new, but it is being done more frequently as the number of gang arrests surges. This is angering some community activists and defense lawyers. They charge that young people in poor communities who have committed relatively minor offenses often are hit with a conspiracy charge under RICO that ties them to more serious crimes by violent gang members. They want the City Council and the city's Department of investigation… to investigate if prosecutors and cops are being too aggressive in going after gangs.