Josephe Murray, 18, of the 5700 block of Reedland Street, was arrested on Wednesday and charged with murder and robbery.
Tom Watson, 36, known as DJ Fenix, was shot and killed at the Haagen-Dazs ice cream shop at 242 South Street around 3:45 a.m. Saturday. Watson's apartment was in the same building.
On Monday, police sources told Action News they found a large amount of cocaine and marijuana in his apartment.
Those sources believe Watson would sell drugs at his performances.
Police sources say they also believe Watson was targeted because of the drugs, because his attackers made no effort to steal his music equipment.
In addition, police sources say, they have surveillance video of the attack and the killers were not wearing masks.
The video shows Watson fighting with his attackers, police sources say, before he was shot multiple times.
Watson worked as a DJ at Tavern 222.
It was not immediately known if any more arrests would be made in this case.