Police say Gregory Smith, 21, was arrested Wednesday in the murder of 21-year-old Dominic Billa.
The shooting happened around 5 p.m. on March 29 after a large fight broke out by the food court inside the mall located on 1400 block of Franklin Mills Circle.
Billa was shot in the chest multiple times and died from his injuries.
Police say surveillance video from inside the mall helped them track down Smith who is facing murder charges.
District Attorney Larry Krasner confirmed last month that Billa was the stepson of a detective assigned to his office's Homicide/Non-Fatal Shooting Unit.
SEE ALSO: Mother speaks out after son killed inside Philadelphia Mills mall: 'My worst fear happened'
"I'll never be the same, never. I'm broken. I'm literally broken," said Billa's mother, Nakisha Billa in an interview with Action News.
"My worst fear happened. My worst fear was of losing my son. That's my worst fear. I did everything I could to keep him protected. I didn't want him to go outside," Billa added.