Troubled state of Virginia Tech killer was known in '05 By Shaila Dewan and Marc Santora Wednesday, April 18, 2007 BLACKSBURG, Virginia: Campus authorities were aware 17 months ago of the troubled mental state of the student who shot and killed 32 people at Virginia Tech on Monday, an imbalance graphically on display in vengeful videos and a manifesto he mailed to NBC News in the time between the two sets of shootings. "You have vandalized my heart, raped my soul and torched my conscience," the gunman, Cho Seung-Hui, said in one video mailed shortly before the shooting at a...