Are you familiar with the term Mens rea? Do you know there is generally no way 'see' or discover a guilty mind until a guilty act (actus reus) is perpetrated?
Of course one might postulate that everyone who owns a gun has established Mens rea and simply needs the right circumstance to kill.
So you're saying that there is no way to establish guilt of a crime, until a crime has been committed?
Why... by God
THAT'S BRILLIANT!
(Reader, there's just no better way to determine that a quality google search has been performed, than to observe a Relativist, using latin.)
Of course, that circumstance suggests that since crime happens as a consequence of a guilty mind, that there exist minds out their who have, are and will be acting out in in ways which threaten the lives of innocent people.
And despite YOU being the one to note this fact of nature, you seem to be indicating that people who arm themselves as a means to avoid becoming the innocent victim, are presenting themselves as guilty, despite the evidence YOU present, arguing that such is not the case, based upon millennia's experience which informs us that a guilty mind requires a guilty action.
Now, man's spirit was created in the image of God. Thus it falls to every man who lives free, thus who possesses the spirit of God, to defend his life and those of others around him; his family, friends and neighbors as he would defend his own life and that of God.
That human life which possesses God's spirit is precious, it follows that such is valuable beyond all else. Yet you're suggesting on the one hand that such is not the case, even as you come to lament 'killing', when all reason argues that killing, in and of itself is a necessity... as it sustains life where such is done to feed us and where such is done to defend innocent life.
So... where does it fit that 'killing' is bad, but not defending one's spirit filled life, is also bad; which is to say to take measures to defend innocent life through the ownership and effective use of a state of the art firearm?
Help a brother out here, will ya?