Jahmir Harris, 23, of the 1600 block of Ringgold Street, was arrested on Sunday and charged with the murder of 45-year-old Louis Porter.
The shooting happened outside the Walgreens Pharmacy on the 2300 block of Oregon Avenue in South Philadelphia on December 23rd.
Surveillance video showed Porter pulling his vehicle into the parking lot with his 5-year-old son in the passenger seat.
As he was about to walk up to the store another car pulled up, the driver got out and fired 17 shots.
Porter was shot in the head.
The video shows the 5-year-old running from the scene into the arms of a bystander. He was not hurt.
Investigators say Harris was identified as a suspect by a witness.
Police have not disclosed a motive for Porter's murder.