Though I agree with you on the issue of capital punishment, you must know that The Church allows for discusion and disagreement in that matter.
However, your argument makes no sense. How can you equate innocence with guilt?! I doubt anyone here is in favor of killing the innocent at any age. And your closing sentence echos a pro abortion argument used in their propaganda, “abortion should be legal if it will save the life of the mother.” This can never be!! Not for any reason!
I suggest you start listening to Catholic Answers Live instead of NPR if you don’t already. Any one of their awesome apologists would be able to go into great detail about what the church really teaches.
It’s not accurate to say that the Church allows for discussion and disagreement pertaining to capital punishment in general terms. Here is what the Catechism says:
"2267 The traditional teaching of the Church does not exclude, presupposing full ascertainment of the identity and responsibility of the offender, recourse to the death penalty, when this is the only practicable way to defend the lives of human beings effectively against the aggressor.
"If, instead, bloodless means are sufficient to defend against the aggressor and to protect the safety of persons, public authority should 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.
“Today, in fact, given the means at the State’s disposal to effectively repress crime by rendering inoffensive the one who has committed it, without depriving him definitively of the possibility of redeeming himself, cases of absolute necessity for suppression of the offender ‘today … are very rare, if not practically non-existent.’[John Paul II, Evangelium vitae 56.]”
So capital punishment is permissible only when it is the only practicable way to defend the lives of human beings effectively against the aggressor. If bloodless means are available, they must be chosen. That is the teaching of the Church, and that is what Catholics must follow.