A gunman who took six girls hostage in a Colorado high school, killing one of his captives and himself, began the siege by ordering students to line up next to a blackboard as he tapped each with his gun and told them to stay or go. Student Cassidy Grigg, 16, said the man walked in, fired a warning shot at the floor and ordered the students to line up. He told some to leave and others – all girls – to stay. “You could tell that he wanted the females,” Cassidy said on NBC’s Today program. Full Story