Hoping to aid the investigation into the killings of two Virginia Tech students last month, a Lynchburg cardiologist has raised $40,000 in reward money since Labor Day. Adding the $10,000 put up by Virginia Tech, the total reward now stands at $50,000. The money is to be paid for information leading to the arrest and conviction of the killer of David Metzler, 19, and Heidi Childs, 18.