I am so fucking tired of this "excuse" If you are too stupid to stand trial for crimes like murder/rape/incest/etc then the outcome is execution. You do not belong in society and I am not giving you a "free pass" because you are a fucking moron.
I am done with this. I also include the "under 18" population. You want to make "adult" decisions/actions you get "adult" punishments. You fucking kill someone when you are 5, 10, 17? You go to jail for life and if the correct states you are executed.