I am not a Catholic and my question was not raised in the context of Catholic dogma. Logically, if this is a question determined by free will, does not execution deprive the true criminal of any chance of exercise of free will by repenting and being saved? What about the prisoner convicted in error - is it not better to "err on the side of life" for these cases?
"Logically, if this is a question determined by free will, does not execution deprive the true criminal of any chance of exercise of free will by repenting and being saved?"
According to traditional Catholic doctrine, the purpose of execution is expiation (murder being an affront to God), not conversion. If the guilty party repents before he is excuted, then so much the better. He may yet save his soul THEN.
"What about the prisoner convicted in error - is it not better to "err on the side of life" for these cases?"
In a word, NO. What you mean is that the occasional incidence of error (statistically small) should be used as an excuse to absolve all proveably guilty persons for answering for their crimes. This would be an even greater injustice to the many more innocent victims of violent murder in the community.
What the h*** are you... a liberal Democrat?
Actually this is the way the reasoning works: The supreme law of the Church is the salvation of souls, not preserving all life (even the guilty) at all cost, not ending all suffering. The sentence of death to a convicted unrepentant criminal forces that person to contemplate the Four Last Things, death, judgment, heaven, hell. Being forced to contemplate these thing may bring about repentance and at least imperfect contrition. Then, in accepting their fate, they can offer up any suffering in union with Our Lord's as reparation for the damage they have caused by their sin.
In the mind of the church there is a worse fate than being put to death, and that is going to going to hell. That a sentence of death can bring about repentance and penance is a good and just thing. It is purely humanistic thinking, that places this life as the supreme good, and this is the thinking behind those opposed to the death penalty in all cases. That is not Catholic.