The suspect was identified by the Chester County District Attorney's Office as 24-year-old Merritt Dudas.
Authorities say he is a long-time friend and neighbor of the victim, 21-year-old Drew Ferguson.
Ferguson's body was found in his apartment, which was in the upstairs of his grandparents' garage, at 222 Miner Street on Monday.
The DA's office said Ferguson was killed on Friday.
Investigators say the killing apparently stemmed from a dispute over drugs.
Furthermore, police say Dudas used a 380 handgun owned by his girlfriend's father to commit the crime.
Dudas was arraigned late Tuesday night in Exton, Chester County.