PHILADELPHIA—A 14-year-old Philadelphia boy waiting for a bus to take him home from school was shot 18 times and killed Monday afternoon, police said. Samir Jefferson was waiting at a bus stop shortly before 3:30 p.m. Monday in a North Philadelphia neighborhood when two unknown shooters fired at least 36 shots, a Philadelphia police spokesperson said in an emailed incident report. Police said Jefferson was shot 18 times throughout his body. The boy died at a local hospital a short time later. The incident report said no motive for the shooting was known as of early Tuesday. But police officials said the shooting outside of a crowded pharmacy was witnessed by a number of people and at least partially recorded on surveillance footage. Officials told WPVI-TV that they had questioned two persons of interest, but as of early Tuesday no charges had been filed. Philadelphia has recorded 508 homicides in …