He was arrested and taken into custody . Man threw popcorn at son , then shot father after argument , Philadelphia Police say . Victim was treated for gunshot wound to left shoulder , police say . Officer Joseph Williams was carrying a .380-caliber handgun , police say .
Man threw popcorn at son , then shot father after argument , Philadelphia Police say . Victim was treated for gunshot wound to left shoulder , police say . Officer Joseph Williams was carrying a .380-caliber handgun , police say .