I recall the national horror and outrage at the time of the Moors Murders, because it was so unusual at that time.
Society moves on - but only one day at a time.
If the judges and judiciary at the time had been able to move forward from that time to today, and see what has transpired, they may have altered their sentencing - we can never know.
But time moves on one day at a time, and we find ourselves in this position as a result of that passage of time, so there is no simple rubber stamp solution to be found here.
I tend to agree with the notion that Brady is not of sufficiently sound mind to make a decision regarding his life or death, and the rules we apply as a society in these cases are not null and void on the basis of his crimes.
If he does know where Keith Bennett is buried, then that is the one small piece of power he has left, and he will die with it, I am sure.