Is "murder" ever morally justifiable?

When it comes to justifying most anything, including murder, evil is in the eye of the beholder. 

     I'm a believer of Frued's idea that as people we inherently justify or rationalize our actions to protect ourselves from any emotional turmoil that could come about from them. People will justify just about any measure of evil as life events filter through their own moral values, the values held by their peers, and weigh against the circumstances driving their actions, their "motives". For instance the housewife who poisoned her late husband's coffee, the cold blooded suicide bomber, and even megalomaniac dictators like Joseph Stalin who had thousands of people massacred, all somehow rationalize their actions. So when asked the question is murder "morally justifiable?" I would say, sure, it just depends on who's asking. To me murder isn't something that you can or should really have to justify. If killing was what a situation came down to, there should be no doubt in my mind that it was a reasonable option given the circumstances, and therefore wouldn't require real "premeditated justification" which really to me indicates that an action was immoral. Of course my idea of what is morally justifiable may not agree with other people's idea of what is. Under the law, most religions, and many people's general moral code all together murder is never morally justifiable; so again, evil is in the eye of the beholder.