I especially recommend Mobbing and the Virginia Tech Massacre. It's easy to think the writer's taking the outsider's side too much, so I'll note this, from his conclusion: "This does not mean trying to excuse Cho's inexcusable crimes. Nor does it mean trying to shift blame and scapegoat somebody else. It means trying to get at the truth of what happened: empirical identification of the sequence of events, what led to what. Sound scientific explanation honors those who wrongly and unnecessarily lost their lives or suffered injury at Virginia Tech on April 16, 2007, and gives promise of preventing repetition of the tragedy."
ETA: From Amanda Howard's "Workplace Homicide":
If we turn a blind eye to toxic relationships at work because we fear being disrespectful to the dead, we are actually doing them an injustice. If positive changes come out of workplace tragedies, then at least those who died did not die in vain. At least we can have some hope that by addressing the complexities behind murders in the workplace, lives can be saved in the future.