It is bewildering, frankly, that so many Catholic Americans urge retaining the use of capital punishment in our own legal system regardless of anything the Church says, all the while they condemn other Catholics for a “cafeteria” approach to Church doctrine, and all the while refusing even to study the reasoning that prompts the Church’s current teaching in this regard.
In short, give human life the benefit of the doubt. Follow the Gospel. Capital punishment halts crime? Prove it."
— Msgr. Owen Campion of Our Sunday Visitor on Catholic opposition to capital punishment