Tom Watson, 36, also known as DJ Fenix, was shot around 3:45 a.m. Saturday inside the Haagen-Dazs Ice Cream shop on the 200 block of South Street.
Police say Watson was going to his apartment located above the shop when he was attacked.
On Monday, police sources say that 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.
Anyone with information is asked to contact Philadelphia Police at 215-686-TIPS (8477), text a tip to PPD TIP (773847) or through PhillyPolice.com.