Catechism of the Council of Trent:
“The power of life and death is permitted to certain civil magistrates because theirs is the responsibility under law to punish the guilty and protect the innocent. Far from being guilty of breaking this commandment [Thy shall not kill], such an execution of justice is precisely an act of obedience to it. For the purpose of the law is to protect and foster human life. This purpose is fulfilled when the legitimate authority of the State is exercised by taking the guilty lives of those who have taken innocent lives. In the Psalms we find a vindication of this right: “Morning by morning I will destroy all the wicked in the land, cutting off all evildoers from the city of the Lord” (Ps. 101:8). (Roman Catechism of the Council of Trent, 1566, Part III, 5, n. 4)
Catechism of the Catholic Church (1992):
“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 peantly, if this is the only possible way of effectively defending human lives against the unjust aggressor.
If, however, non-lethal means are sufficient to defend and protect people’s safety from the aggressor, authority will limit itself to such means, as these are more in keeping with the concrete conditions of the common good and more in conformity to the dignity of the human person.
Today, in fact, as a consequence of the possibilities which teh state has for effectively preventing crime, by rendering one who has committed an offense incapable of doing harm – without definitely taking away from him the possibility of redeeming himself – the cases in which the execution of the offender is an absolute necessity ‘are very rare, if not practically nonexistent.'”
Pope Francis 2018:
“Recourse to the death penalty on the part of legitimate authority, following a fair trial, was long considered an appropriate response to the gravity of certain crimes and an acceptable, albeit extreme, means of safeguarding the common good.
Today, however, there is an increasing awareness that the dignity of the person is not lost even after the commission of very serious crimes. In addition, a new understanding has emerged of the significance of penal sanctions imposed by the state. Lastly, more effective systems of detention have been developed, which ensure the due protection of citizens but, at the same time, do not definitively deprive the guilty of the possibility of redemption.
Consequently, the Church teaches, in the light of the Gospel, that ‘the death penalty is inadmissible because it is an attack on the inviolability and dignity of the person’, and she works with determination for its abolition worldwide.”
So the Church has been wrong for 2000 years on the Death Penalty. Got it.