These incidents always have a reference to the Columbine shooting... Even in that article just randomly stuck on the bottom there. I think people should start looking outside this incident!
Did you see the part where this school was only a short drive from columbine?
But do you still think it was influenced by the Columbine High School shooting? I say even if it was across the road it wouldn't matter, it's all in the minds of the people doing it. I doubt they are copy cats, just someone who sets their beliefs on something they have been brainwashed (possibly by themselves) into.
See now the BBC version that Kujo has posted points to something a little better. "The police said there were indications that he was motivated by an incident that happened some 20 years ago." This is why I think everyone shouldn't look at the Columbine Shooting as a catylst for these events, rather a domino trigger.