Heh I don't care either way (with regards to the question). What that collection of writings say has been said since the beginning of human society.
Do something the group as a whole agree on is good, and the killing is justified. something the group think is bad, it ain't.
The Christian doctrine acknowledges this. The debates I've had with apologetics regarding this topic always start out with them explaining that the Hebrew meaning is "murder", not "kill". Since a murder is an unlawful killing, we're down to group dynamics and social interaction and the rules within those.
Personally, I've been forced away from the easy answer of "what does [insert religious document] say on this?" (each to his own) and into the realm of cultural relativism. Of course, there are universals here, and unlawful killing is one of those that have been around in every major culture since the dawn of time. Social animals need "rules of conducts", if you will, to ensure the continuation of the species.
In the US the death penalty is an accepted norm within the group. In most European countries, it ain't.
The way I see it; you kill anything, you're a killer. You kill another human, then you cross a cultural taboo that's been encoded in us, and you'd need certain conditioning to be ok with it. The quick answer is that technically, the lawful killing of another person doesn't make you a murderer. On a more abstract leve, technicalities aside, the case is less clear cut, at least to me.
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StSanta
JG54 "Grünherz"