I can't help but find this story funny. It could be be a sitcom plot, infact I think there was an episode of Malcolm in the Middle where something like this happened, except the kids got away with it...
and plastic handcuffs, that's funny because any child of five can figure out the button that opens them or else they can just break them. And I know this is like a violent serious offense sort of thing, but this at least proves that not all of America's children are completely stupid, these kids had a goal, made a plan and organised themselves to carry out the plan, but it would be nice if the goal wasn't kidnapping and murder.
Does that paragraph make me sound like a sociopath or something? I hope not. I'm not encouraging the act of kidnapping/murder, just the planning and self organisation part.