I'm still not convinced that 9 year olds could cut up a body. Average nine year old is 4'6" 70lbs. I'd have trouble cutting human bone with a steak knife. Christ sake, are you forgetting how weak you are before puberty? They obviously didn't think it all the way through, again, they're not even top notch 9 year olds ; how intricate do you suppose their plan was? I'd say, not very.
These kids are just stupid as hell, guys. I'd say I was even more diligent as a young boy than I am as a young man. Not because I knew more about punishment back then, but because, whether from my parents or otherwise, I had a conscious knowledge of wrong and right. I knew that it would be a major fuck up, and that I would be punished. Although I may not have known as much as I do today as far as academics go, I definitely fucking knew that it's a BIG mistake to kill someone. On top of that, why would I want to hurt anyone? Sure, I watched Dragon Ball, Mortal Kombat and Spawn... But I still never got into any real fights, nor did I want to hurt anyone.
It would be perplexing to figure out why average 9 year olds from decent middle-class families would do something like this. It's not as shocking to understand that a bunch of LD 9 year olds would think up a plan like this. Chances are they didn't have great parenting, either. Also, kids who have ADD severe enough to be in a separate class aren't much brighter than those with ADD.
Idiocy+Innocence+Mob Mentality=Let's kill someone, I suppose.