Killing abortionists? No thanks. But why?

There's a long, interesting discussion going on in the comments of this post at Mark Shea's place about killing abortionists. It's an issue, of course, because Paul Hill was executed in Florida this week for his murder of an abortionist and his bodyguard.

I'll post my comments momentarily, but I want to reiterate what I state therein: I oppose the killing of abortionists. And I believe that Hill's action was murderous, i.e. there is no way to legitimize it as morally licit. Kevin Miller's comment is right on: "Hill didn't want to defend babies. He wanted to kill an abortionist. After the man was down, Hill pumped several more shots into him to make sure he was dead. That's called murder - morally as well as legally. In general, ambushing and shooting someone is not to be confused with using (lethal) force in defense. There is no double standard."

Having said that, here are my comments:

Disclaimer: I believe it's wrong to kill abortion doctors.

Having said that, I also think that we need to do a better job of elucidating our opposition to the actions of people like Mr. Hill.

Fr. Johansen linked the argument made by Fr. Walsh, which is very solid in many ways. At the same time, it still leaves certain questions unanswered. For instance, in his discussion of the right of defense of an innocent third party, Fr. Walsh points to the work of early 20th century moralist Hieronymus Noldin, who argues that a forceful defense of a 3rd party is only licit when the third party is someone related to the person taking defensive action or is a holder of public office, like a police officer. But what is the basis for such an assertion? I recognize Noldin's (and Walsh's) point, but what is the justification for such a stance. Would it then be illicit for a German resistance fighter to use (potentially lethal) force against a Nazi guard who is about to kill a concentration camp prisoner, simply because that prisoner is neither related to the fighter, nor a holder of public office?

Fr. Walsh also points to Noldin's statement that forceful defense may be employed only at the actual moment of the attack. While I again recognize the intention, this seems difficult to understand in real-life circumstances. Take the Nazi example again: if the attack occurs indoors, is the resistance fighter morally prohibited from using force against the Nazi before he enters the bulding wherein he will kill an innocent person?

Perhaps the answer to this and the other questions is an affirmative one; either way, I think it's important for us to grapple with these sorts of questions to ensure that our opposition to the acts of Mr. Hill et al does not also require opposition to other acts which we may be inclined to accept as morally permissible.