The Death Penalty - in the Catechism:
scborromeo.org/ccc/p3s2c2a5.htm#2267
Pope St. John Paul II
"Today however, as a result of steady improvements in the organization of the penal system, such cases are very rare, if not practically non-existent.
In any event, the principle set forth in the new Catechism of the Catholic Church remains valid: “If bloodless means are sufficient to defend human lives against an aggressor and to protect public order and the safety of persons, public authority must limit itself to such means, because they better correspond to the concrete conditions of the common good and are more in conformity to the dignity of the human person”"
(
w2.vatican.va/content/john-paul-ii/en/encyclicals/documents/hf_jp-ii_enc_25031995_evangelium-vitae.html number 56)
Can one campaign for the abolition of the DP? Yes.
In fact Bishops and Popes have sought to intervene in cases.
Pope Francis has very much been against its use these days. That it is “impossible to imagine” basically the States not having the means to protect the public in other ways.