It was pretty good, but a little off
It was actually really good. It was one of the best Columbine things I've seen. Yeah, there were a few things off, like the Manson thing on his backpack. Eric and Dylan both hated Manson! And you left out the stuff about the pipe bombs and the trench coats, but that's okay. It doesn't have to be perfect. I don't know why you changed the names, though.
Over-all, it was good.