I'll take a wild guess that they're a variant of the Columbine kooks.
A little older, perhaps, but basicly pathetic losers whose warped jack@$$ "logic" tells 'em that it'd be "cool" to reenact the stuff they watch on TV.
Remember: whacknuts don't behave rationally. That's why they're whacknuts.
What you said makes sense too. I wish the girl that was just interviewed on Fox with Rita Cosby would have taken a guess at the guys age.