An excellent post at the Catholic Advocate concerning capital punishment, an issue that Catholics have struggled with, though the teaching of the Church consistently supports its use as appropriate under certain conditions.
“The Death Penalty (Chapter VIII)
“Assuming that the guilty party’s identity and responsibility have been fully determined, the traditional teaching of the Church does not exclude recourse to the death penalty, if this is the only possible way of effectively defending human lives against the unjust aggressor” (CCC 2267).
“Capital punishment is probably the most misunderstood moral issue in the Catholic Church. This confusion stems from the change made in the Catechism in 1997 to bring the teaching into conformity with the encyclical Evangelium Vitae (1995).
“The change was widely reported in the media and by some Catholic commentators as the Church declaring total opposition to the use of the death penalty. This view is not supported by the words of the revised Catechism or Evangelium Vitae itself.
“The Church’s position can be summarized in this way: The Church is not opposed to the death penalty in principle but in practice. To oppose the death penalty in principle would be to remove one of the most basic responsibilities of the common good—to provide defense and security against aggression.”