The Pope and the Death Penalty

Here. 

So, in the end is the Pope changing Church teaching by arguing against capital punishment? Absolutely not! It fact, it would be contrary to Church teaching to say that  capital punishment is per se immoral, as some do. Rather, the Pope states that the conditions of modern society argue against it's use in all but rare cases. It is simply becoming harder and harder to argue that a particular act of capital punishment is circumstantially necessary (the third element of a good moral act).