Hmmm...

I can't believe ABC is publishing this:

Contrary to public perception, school shootings declined after 1993, although there were copycat incidents from 1997 to 1999 "stimulated" by unprecedented media coverage, according to the National School Safety Center.
...
Some of the conclusions of the federal report were borne out in the Virginia Tech tragedy: shooters tend not to snap, but usually plan months or years in advance and often tell a friend or classmate.

Interesting article, actually. Discusses the difference between psychotics and psychopaths, and what motivates serial killers and mass murderers.