IYAS9YAS: "Yes. There are many places in the Bible where killing was just, and necessary."
It's simply the difference between just and unjust taking of lives.
Murder, by definition, is unjust killing.
But the Old Testament requires death as a just penalty for capital crimes, including murder.
So when people use "Thou shall not kill" as an excuse to, for examples, abolish capital punishment or refuse participation in all wars they are, yet again, abusing the Bible's intended meanings.
I find several levels of such abuse: ignoring God's word altogether, altering it to fit one's agenda, misinterpreting it to fit one's agenda, lazily failing to interpret it properly, etc. But there are also several levels of believers' response, ranging from casual indifference to unhealthy preoccupation.
Lately I've been memorizing the Letter to the Hebrews as my first extended memorization project--I'm in chapter 12--and now I'm contemplating, I trust under the Holy Spirit's guidance and inspiration, tackling Romans soon. Although I understand that we will soon be in the Lord's physical presence, I also know that we'll have 1,000 years before the end comes, a millennium in which, if we wish, to memorize (and apply, of course) the entire Bible, so I'm just getting a head start. Since Hebrews has only taken me four months, I think I could manage the whole thing in ten centuries. For example, even though Job has 42 chapters, it was created five hundred years before Hebrew became a written language, so it was made to be memorized (especially if you're a shepherd overseeing your flock on a hillside with no TV, phones, etc.). Makes me want to do Job after Romans...
I'm finding that memorization necessitates and produces a greatly increased personal appreciation for and understanding of passages in Hebrews now that I know them so intimately, which makes, as you said, "abusing the Bible's intended meanings" nearly impossible now.