Which fact is difficult to discern among the many calls from bishops, popes and Catholic news outlets calling for its abolition; but, in response to the latest abolition call, the superb article from The Catholic Thing summarizes the source of the traditional teaching supporting capital punishment.
The tradition of support for capital punishment by the Church is also surveyed in the Lampstand book: Capital Punishment & Catholic Social Teaching: A Tradition of Support. For links to all Lampstand books at Amazon go to http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=david+h+lukenbill
An excerpt from the Catholic Thing article.
A group of Catholic publishers recently issued a joint statement urging an end to capital punishment. I have great respect for all of them – I have written for all of them at one point or another. I disagree with them on this issue, however. And it may be good to give some background about why I and many others disagree.
Most importantly, the Catholic Church’s Magisterium does not and never has advocated unqualified abolition of the death penalty. The U.S. bishops have conceded that Catholic teaching has accepted the principle that the state has the right to take the life of a person guilty of an extremely serious crime. Even the late Cardinal Joseph Bernardin – hardly a conservative – never stated that every criminal has a right to continue living, nor did he deny that the state has the right in some cases to execute the guilty. St. John Paul II, although opposed to most applications of the death penalty, thought the same.
Let’s hear what St. Augustine had to say on this topic: “ . . . there are some exceptions made by the divine authority to its own law, that men may not be put to death. These exceptions are of two kinds, being justified either by a general law, or by a special commission granted for a time to some individual. And in this latter case, he to whom authority is delegated, and who is but the sword in the hand of him who uses it, is not himself responsible for the death he deals. And, accordingly, they who have waged war in obedience to the divine command, or in conformity with His laws, have represented in their persons the public justice or the wisdom of government, and in this capacity have put to death wicked men; such persons have by no means violated the commandment, You shall not kill.” (City of God, Bk I, 21)
Augustine also said that capital punishment protects those who are undergoing it from further sinning, which might continue if their life went on.
If this is not enough, consider the thoughts of the Angelic Doctor, St. Thomas Aquinas, on this topic. Citing Exodus 22, which specifies that certain categories of wrongdoers shall not be permitted to live, Aquinas unequivocally states that civil rulers can execute justly to protect the peace of the state. St. Thomas finds frivolous the argument that murderers should be allowed to live in hopes of their repentance, questioning how many innocent people should have to suffer death while waiting for the guilty to repent. While capital punishment is not justifiable as an act of vengeance, according to Aquinas it is justifiable to help secure the safety of the community by removing a dangerous wrongdoer and deterring others from his example; in addition, it is an act of justice, allowing expiation for the wrongdoer’s sin.
Retrieved March 16, 2015 from http://www.thecatholicthing.org/2015/03/16/the-traditional-case-for-capital-punishment/