UPPER MACUNGIE TOWNSHIP, Pa. - Authorities still don’t know why a man opened fire at a convenience store in Pennsylvania last week, killing a truck driver who was pumping gas and wounding another man before taking his own life.The Lehigh County district attorney’s office on Wednesday released more details about the shooting spree but said the suspect’s electronic devices, including his cellphone, revealed no information about the crime or a motive.Za Uk Lian first shot at a car on a highway several miles away before heading to the Wawa convenience store in Upper Macungue Township, outside Allentown, around 4:45 a.m.