PHILADELPHIA -- A homeless veteran, beaten at a gas station in the Olney section of Philadelphia nearly eight months ago, has died.The incident at the Sunoco in the 5500 block of North 5th Street was captured by a surveillance camera on April 7 The video shows 51-year-old Robert Barnes being pummeled by teens with a hammer, a piece of wood and punches, after police say a 10-year-old boy told his mother he got into an argument with Barnes.The attack left Barnes in a coma.The boy's mother, 34-year-old Aleathea Gillard, has been charged in the case, along with 24-year-old Shareena Joachim.Three juveniles were also arrested and charged with attempted murder, aggravated assault, simple assault and related offenses.Police say those charges could be upgraded to murder after the district attorney returns from the Thanksgiving holiday.