By Yohance Kyle, Allhiphop.com, Aug. 20, 2013

For more conventional and far more detailed reporting on this story, also see:

Seized Guns Offer Look at Pipeline From South
By J. David Goodman, New York Times, August 19/20, 2013

I admit it was this excerpt from the NYT that led me to find the Allhiphop.com story:

Many of the deals with an undercover officer took place at a music studio in Ocean Hill, Brooklyn.

It was in part because of social media images posted by an aspiring rapper, Matthew Best, 26, who used the studio and allowed gun sales to take place there, that detectives first homed in on the operation, according to the police commissioner, Raymond W. Kelly. Mr. Kelly said that in a YouTube clip, Mr. Best “boasted of ‘packing more guns than the Air Force.’ ”

There's lots more TV-series-caliber content involved, like using the notorious Chinatown buses....and stuff like this:

During the investigation, which emerged last August from an unrelated drug case, the undercover detective watched as two of the suspects struggled to assemble an assault rifle during a sale. They even looked at an instructional video on their smartphone, said Bridget G. Brennan, the city’s special narcotics prosecutor, before the detective agreed to buy the gun in pieces.