Since the church has always recognized the death penalty as a just sentence it is inappropriate to suggest that people who support its use in this case are unmerciful.
Yet, the Church’s ‘support’ for the death penalty these days is more fully developed than it was earlier in its history. I think it
is appropriate “to suggest that people who support its use in this case are unmerciful,” given what the Catechism has to say about it:
"Assuming that the guilty party’s identity and responsibility have been fully determined, the traditional teaching of the Church does not exclude recourse to the death penalty, if this is the only possible way of effectively defending human lives against the unjust aggressor.
If, however, non-lethal means are sufficient to defend and protect people’s safety from the aggressor, authority will limit itself to such means, as these are more in keeping with the concrete conditions of the common good and more in conformity to the dignity of the human person.
Today, in fact, as a consequence of the possibilities which the state has for effectively preventing crime, by rendering one who has committed an offense incapable of doing harm - without definitely taking away from him the possibility of redeeming himself - the cases in which the execution of the offender is an absolute necessity ‘are very rare, if not practically nonexistent.’" (CCC, 2267)
All judgment is not forbidden, only judgement about things we cannot know, and there is surely no doubt about what Gosnell has done.
But “what Gosnell has done” is not the object of “judgment about things we cannot know.” Rather, “what we cannot know” has everything to do with his interior disposition (and, quite significantly, the prospects for his repentance and conversion). Can we judge that he will not repent and turn toward God if he is given a life sentence rather than capital punishment? If not, then the death penalty isn’t just, from a Christian perspective. (And I’m pretty sure we can all agree that knowledge of the future is firmly in the realm of “things we cannot know.”

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