I gotta say I never understood the whole not trying them as adults thing.
I get that kids brains aren’t fully developed and that can lead them to do some morally apprehensive things but that just sounds like a bullshit excuse. That’s an excuse meant to be used for shit like stealing a candy bar or mild vandalism not beating someone to death.
Honestly I think the parents of the child should also end up with legal ramifications. You raised a piece of shit now you get to deal with the consequences.