Marble was last seen at his home on Marlboro Road in Brattleboro, Vermont on August 27, 2011. At 1:15 p.m., one of his housemates heard him answer the door and invite an unknown man inside. He apparently left the house sometime afterwards, leaving a note saying he was going out for a walk and would be back shortly. He was supposed to meet his girlfriend at 4:00 p.m., but never showed up. He has never been heard from again.