This WaPo article describes some of Cho Seung Hui’s behavior at Virginia Tech. You can read more about his creepy creative writing here, with some general perspective from those who teach creative writing here. There were people who tried to reach out to him and help him:
[Virginia Tech creative writing professor Lucinda] Roy, 51, said in a telephone interview that she also urged Cho to seek counseling and told him that she would walk to the counseling center with him. He said he would think about it.
Roy said she warned school officials. "I was determined that people were going to take notice," Roy said. "I felt I’d said to so many people, ’Please, will you look at this young man?’ "
Roy, now the alumni distinguished professor of English and co-director of the creative writing program, said university officials were responsive and sympathetic to her warnings but indicated that because Cho had made no direct threats, there was little they could do.
"I don’t want to be accusatory or blaming other people," Roy said. "I do just want to say, though, it’s such a shame if people don’t listen very carefully and if the law constricts them so that they can’t do what is best for the student."
The law apparently limits what we can do and, as noted in this WSJ editorial, is itself limited in what it can do.