268 “The arguments against the death penalty are numerous and well-known. The Church has rightly called attention to several of these, such as the possibility of judicial error and the use made of such punishment by totalitarian and dictatorial regimes as a means of suppressing political dissidence or persecuting religious and cultural minorities, all victims whom the legislation of those regimes consider ‘delinquents’. All Christians and people of good will are today called to work not only for the abolition of the death penalty, legal or illegal, in all its forms, but also to work for the improvement of prison conditions, out of respect for the human dignity of persons deprived of their freedom. I would link this to life imprisonment… A life sentence is a secret death penalty”.
Source: Fratelli Tutti (Vatican.va)