the difference between 17 and 18

[lookout123]

if i understand correctly this was not an issue of all 16 year old being eligible for lethal injection. 18 is the standard, but there are cases where someone younger knew exactly what they were doing, chose to do it and deserves the same punishment that someone over 18 deserves. this ruling is saying that if someone is 17 they can jump up and down and scream at the top of their lungs "i am going to commit XYZ crime! i know what i'm doing! you can't put me to death because it's not my birthday!"

i know that is extremely unlikely and even ridiculous, but according to this ruling, even in that case, the individual cannot receive the death sentence.