In 2018, Pope Francis promulgated a change to the Catechism making the death penalty “inadmissible.” Few know less than fifty years ago it was legal in the Vatican.
When the Lateran Treaty was signed in 1929, the Italian legal code concerning attempted assassinations on the King was copied over. In the newly formed Vatican City State, that meant any attempted assassinations on the Pope carried with it capital punishment.
Article 8 of the Lateran Treaty reads:
“Considering the person of the Supreme Pontiff to be sacred and inviolable, Italy declares any attempt against His person or any incitement to commit such attempt to be punishable by the same penalties as all similar attempts and incitements to commit the same against the person of the King. All offences or public insults committed within Italian territory against the person of the Supreme Pontiff, whether by means of speeches, acts, or writings, shall be punished in the same manner as offences and insults against the person of the King.”
There were no attempts on the pope’s life while this statute of the Treaty was in effect however.
In 1969, Pope Paul VI removed the capital punishment statute from the law of the Vatican City, and when Mehmet Ali Ağca attempted to assassinate Pope John Paul II a little over 20 years later in 1981 he was tried in an Italian court rather than in the Vatican.
Rarely the right answer but should always be an option. Some people are simply too dangerous or too evil.