Another source familiar with the case said the two may have argued over a woman.
Gore, a father of two young children, had no criminal record. His father is a veteran officer assigned to South Philadelphia's Third District.
Gore had just picked up lunch from a takeout store and was walking with his girlfriend near 55th and Hunter Streets when a man police believe was Gey ran up to him and opened fire. Gore was hit six times, including a shot to the heart, and died at the Hospital of the University of Pennsylvania.
Police initially had few clues, and said Gore seemed so unlikely a target that investigators believed his killing may have been a case of mistaken identity.
This week, a task force assigned to the case returned to the neighborhood. Knocking on doors and talking to neighbors yielded four witnesses, several of whom were able to identify the alleged gunman by name, Wilkins said.
After police went to Gey's home Friday morning and took him into custody, they spoke to Gore's father.
"He thanked us," Wilkins said. "There was some relief at the news."
Contact staff writer Allison Steele at 215-854-2641 or firstname.lastname@example.org.