From the first edition of the Catechism of the Catholic Church in 1992 to the second edition of 1997, the Catechism, the magisterial heart of the Church, moves from clear support of the use of capital punishment by affirmation to muddy support by deprecation.
This is a significant movement and one wonders what led to this change.
We know that the new and more restrictive language on the use of capital punishment in the second edition originated from the encyclical of Pope John Paul II, Evangelium Vitae, of March 25, 1995, and for an explanation of the change in language, we have the words of Joseph Cardinal Ratzinger (Pope Benedict XVI) who presided over the Interdicasterial Commission for the Catechism of the Catholic Church, responsible for overseeing the publication of the Catechism, reported by Fr. Richard John Neuhaus in First Things, The Public Square: A Clarification on Capital Punishment (1995): “Clearly, the Holy Father [John Paul II] has not altered the doctrinal principles which pertain to this issue as they are presented in the Catechism, but has simply deepened the application of such principles in the context of present-day historical circumstances. Thus, where other means for the self-defense of society are possible and adequate, the death penalty may be permitted to disappear.”
Lampstand published a book on this: Capital Punishment & Catholic Social Teaching: A Tradition of Support which explores the issue in depth.
In a recent post at Catholic Culture, the issue is noted in relation to when the Holy Father speaks infallibly.
“Quite apart from the pope’s intention, there are large areas in which Christ has not promised to protect the pope’s utterances, and equally large areas in which the Holy Spirit is not bound by the nature of the Church to protect the pope from error. If the pope chooses to comment to the whole Church about some situation in the world which is not a matter of faith and morals (such as opining, as John Paul II did, that modern penal systems make the death penalty mostly unnecessary), he has no special protection. He may be right or wrong, and the faithful may agree or disagree. If he teaches theology to a particular class, or makes a spiritual point to a group of pilgrims, or argues a point of doctrine in a private letter to his best friend, the Holy Spirit can see there is no risk of binding the whole Church. In other words, whenever the pope is speaking in his private capacity as a man, or is not addressing the entire Church, or is discussing something other than faith and morals, he is not infallible.”