There is a very robust debate countering both the Church's 20 year old anti death penalty teachings (CCC, amended 1997) and the statements by Pope Francis, both of which are contradicted by fact, reason, the Gospel and 2000 years of Catholic teachings, through today, as detailed.
All Catholics may support the death penalty and more executions, today, and remain Catholics in good standing (1).
2) The Catholic Church cannot reverse 2000 years of pro death penalty teachings (2016-2017) (2).
For 2000 years, the Catholic Church has taught that the death penalty is a morally licit, just, appropriate, if not obligatory, sanction.
All of a sudden, since 1997, Bishops are telling us that the death penalty is unjust and cruel. Not only is that not true but, based upon those 2000 years of teachings from Popes, Saints, Doctors and Fathers of the Church, church leadership, biblical scholars and theologians, it cannot be true.
Saint (& Pope) Pius V, "The just use of (executions), far from involving the crime of murder, is an act of paramount obedience to this (Fifth) Commandment which prohibits murder." "The Roman Catechism of the Council of Trent" (1566).
Archbishop Charles Chaput (2005): “Both Scripture and long Christian tradition acknowledge the legitimacy of capital punishment . . . " "The Church cannot repudiate (the death penalty) without repudiating her own identity." (3)
3) The factual and rational problems within the Church's newest death penalty teachings have been well known since the Catechism's CCC 2267 was first amended (1997) (4).
4) The Bishops use well known, false anti death penalty claims to support their positions, which are, easily, rebutted, here (5).
Dead Man Walking & The Death Penalty
1) "3. Not all moral issues have the same moral weight as abortion and euthanasia. For example, if a Catholic were to be at odds with the Holy Father on the application of capital punishment or on the decision to wage war, he would not for that reason be considered unworthy to present himself to receive Holy Communion. While the Church exhorts civil authorities to seek peace, not war, and to exercise discretion and mercy in imposing punishment on criminals, it may still be permissible to take up arms to repel an aggressor or to have recourse to capital punishment. There may be a legitimate diversity of opinion even among Catholics about waging war and applying the death penalty, but not however with regard to abortion and euthanasia."
"Worthiness to Receive Holy Communion: General Principles", from then Cardinal Ratzinger (now Pope Emeritus Benedict XVI) Prefect of the Congregation of the Faith, the top authority of the body responsible for promulgating and defending Catholic doctrine, in a memorandum to Cardinal McCarrick, made public in the first week of July 2004.
By Man Shall His Blood Be Shed: A Catholic Defense of Capital Punishment (2017), Edward Feser & Joseph Bessette
Why the Church Cannot Reverse Past Teaching on Capital Punishment, Profs. Edward Feser and Joseph M. Bessette, The Catholic World Report, July 17, 2016, http://www.catholicworldreport.com/Item/4928/why_the_church_cannot_reverse_past_teaching_on_capital_punishment.aspx
Four Catholic Journals Indulge in (anti death penalty) Doctrinal Solipsism, Steven Long, THOMISTICA, March 5, 2015
The Death Penalty: Mercy, Expiation, Redemption & Salvation
New Testament Death Penalty Support Overwhelming
BISHOPS HIDE TRUTH FROM THEIR FLOCK: DEATH PENALTY
Catechism & State Protection
Why the Death Penalty is Still Necessary, Profs. Edward Feser and Joseph M. Bessette, The Catholic World Report, July 21, 2016
5) Rebuttal to all the Church's secular anti death penalty nonsense
Catholic Bishops: So Wrong on Death Penalty
The Death Penalty: Fair and Just
The Death Penalty: Justice & Saving More Innocents
The Death Penalty: Saving Innocent Lives