From what we know publicly at this hour about the Virginia Tech school shooting, it looks to me like the already building criticism is misplaced.
We have what appears to be a dorm shooting. A man appears to have been angry at his girlfriend or ex-girlfriend and shot her and another man. Then, the shooter reappears two hours later across campus and begins killing randomly in classrooms.
If the dorm shooting scenario is correct, and police had good information about it, it would not follow logically that the shooter would threaten classrooms across campus. It would be much more likely that the killer would flee. After all, if the dorm killer was intent on mass killing, why didn't he continue shooting there?
Tragically, authorities were wrong. But until we know more, I won't be one of the critics.