He's obviously very deeply disturbed. Am I a bad person for hoping they draw this case out till he turns 18 so he could be tried as an adult

Or choose to try him as one anyway... Someone like this doesn't even need to see the light of day tbh, like
RIP to the poor babygirl

And sympathy for her family, I have young nieces I live with and if someone did this I would just have to kill him myself.