The cost of his incarceration has already impoverished many people over time, what's a few more.
No death penalty, no justice, no closure.
"Justice delayed is justice denied", for everyone.
Actually, no.
The cost of litigating a death penalty case over 50 years cost FAR more than incarerating him for 50 years.
Executions aren't justice, they are revenge.
And inevitably, they will execute an innocent person. In fact, they probably already have.