I would say that there are people who have suffered worse who did not commit crimes deserving of the death penalty.
Even when an entire society was Catholic, there were still criminals. Some even come from “ideal” backgrounds: the American Psycho guy, Leopold and Loeb, are two well-known cases that spring to mind.
Additionally, some very good people come from very bad backgrounds. “The fault lies not in the stars but in ourselves,” no?
However, to paraphrase something a bishop said, the problem will not be solved until more of us become saints. How can a society have life and grow if the individuals in the society are spiritually dead?