Doesn't this involve the "defense of another" defense to killing someone? Just like in "self defense" you are morally and legally justified in using the amount of force reasonably necessary to confront and prevent the danger. If you have a reasonable and justifable fear that the family is in imminent danger of being killed, then you have the right to kill the person who poses the threat. "Luring" him to the window simply gives you the opportunity to exercise the right. There is no moral law or code of ethics which says "luring" another person is per se wrong. The circumstances dictate the answer to such a question. If you daughter was kidnapped would it be morally wrong to "trick" the kidpnapper into telling you where she was?!?
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