Could paperwork have sparked the shooting spree that killed four people and wounded 16 earlier this week? Witnesses and relatives of the victims are saying that alleged shooter Spc. Ivan Lopez—who also shot himself—became frustrated when he asked for a leave-of-absence application from a human resources office at Fort Hood and was told to come back the next day. Lopez reportedly left the office for a few moments before returning with a semiautomatic pistol and opening fire. The gunman’s real motive for the shooting remains a mystery.