No one knows the motive for the shooting at this time, but here is some key poinits to keep in mind:
The students and faculty were barricading themselves in their classrooms after what one person described as an Asian student wearing a vest opened fire.
The shooter was "wearing a vest covered in clips was just unloading on their door, going from classroom to classroom … they said it never seemed like it was going to stop and there was just blood all over," Harrison said.
Source: FoxNews: 16 APRIL 2007: Police: 22 Dead After Virginia Tech University Shooting
An "Asian" student wearing a "vest covered in clips" -- definately a pre-meditated attack, where the killer was going for maximum casualties.
It will be interesting to find out who this gunmen was, and his background...
In the meantime, my sincere condelences and sympathy to those family and friends of the victims.