Reidenbach was last seen at her after-school job in Evans City, Pennsylvania on September 22, 1981. She left her job at 4pm to walk to a pharmacy located a half-block away, to buy some cold medicine. She then intended to return to the store. The clerk told police that Reidenbach bought cold medicine and left the store. Michele was last seen at a supermarket parking lot on South Main Street in Zelienople. It was the last confirmed sighting of her. She was last seen wearing blue jeans; a wine-colored, V-necked sweater and a gold necklace with a knot pendant.