Yes, the SCOTUS ruled that a minor cannot be given the death penalty.
However, thanks to FReeper pogo101 (An attorney) I found out that the same decision also forbids life without parole for perps under 18.
So my guess he gets a good attorney, and beats the "life" rap.
Oh, the perp will probably spend 30 years in prison, but he'll eventually be released.
Whatever is left of him that is.
My bet is the perp will WISH he got the death penalty.
The cons will just love to get their hands on him.