Police say increasingly younger and more violent street gangs are responsible for about 40 percent of shootings here in the city.
Investigators say there are more than 300 crews across the five boroughs, with members as young as 12 years old.
Most of them are clustered in or around a particular block or housing project.
Police say the trend towards smaller and younger gangs is a result of crackdowns on larger, more sophisticated groups.
They say violence among younger crews can be sparked by even the smallest incident, like insults on Facebook and Twitter.
The NYPD launched Operation Crew Cut in 2012, with the goal of gathering information about youth gang activity through traditional street policing, trolling social media and by monitoring jailhouse calls.