I have the last couple of days writing a blog entry regarding copycats of the VA Tech shootings -- unfortunately, I can't get it to flow to my satisfaction.
Fortunately, someone with a lot more experience in the subject has done the work for me:
Loren Coleman's Blog: The Copycat Effect.
Read the article linked above, then go back and read the archives.
Tip of the Stetson to Peter for e-mailing me the link.