new information emerged that may help explain a fateful two-hour delay by university officials in warning the campus of a gunman at large. According to search warrants and statements from the police, campus investigators had been busy pursuing what appears to have been a fruitless lead in the first of two shooting episodes Monday.

Two female students at Virginia Polytechnic Institute complained to authorities about the behavior of Cho Seung-Hui, the killer in the shooting rampage there, in separate incidents in 2005 and he was then sent to a mental health facility, but no charges were filed against him.

In a news conference today, the police revealed more details about the 23-year-old students who was named as the gunman in the shooting rampage in which 32 people were killed. Mr. Cho also died, shooting himself in the face at the end of the spree.