Is Murder Ever Right?

I heard some news this morning that got me thinking...

On September 28th of this year, protesters in Guinea filled a stadium to demonstrate against current ruler Captain Moussa Dadis Camara's military junta running for office in upcoming elections. He came to power via coup last December under claims he would not be running for election.

In response to the protest, the government opened fire on the protesters. Anywhere from 57-157 have been counted dead, depending on whose numbers one looks at. The worse part though is not the dead, but the living. The soldiers began to rape women in the stadium out in the open, in the light of day. After raping them, many soldiers put their guns up the womens' vaginas and either fired shots or caused severe damage. Additionally, they brought some women back to various locations and locked them up for rape multiple times per day.
http://www.npr.org/templates/story/story.php?storyId=113966999

In response, there have been some vigilante killings of soldiers.
http://af.reuters.com/article/topNews/idAFJOE59M0HD20091023

This brings up the question: Is murder ever right? I do not mean is murder ever justifiable. If someone had family involved in this atrocity, I would say they are undoubtedly justified in wanting to see the perpetrators killed.

I am taking this a step further.

In this case, or any comparable cases like it, is murder the RIGHT choice? That is, when one allows oneself to commit such utterly sick acts for which there is no justification, does he give up his right to life? Not that the raping soldier is conscious of this decision, but still, in the grand scheme of things, after violating humanity to such a degree, does not the raping man's life become worthless, at least in the eyes of the victims and their families?

In general, most people would say that murder is wrong. Although, do cases such as the Guniea massacre create extenuating circumstance for the morality of murder? Anyone who answers 'no' can probably understand the sentiment of the person who answers 'yes' and vice versa.

Where does this leave us? What is right and what is wrong? Can we use absolute terms to characterize morality or is it a case by case endeavor? The soldiers in Guinea were unquestionably 'wrong', so in that sense, morality can be objective. But, were the vigilante pursuers of revenge who murdered the raping soldiers 'wrong'?

When objective answers are unobtainable, all humanity is left with is a subjective rationality. We are given the facts (rationality) and left to deduce what we can from them (subjectivity). In the Guinea case, the facts are undeniable. What happened, happened. How one should respond though, is purely subjective.

The righteous vigilante thinks he is right, while the mother of the rapist, per se, doesn't want to see her son die. Viewing this through the lens of subjective rationality, both the mother and the vigilante have understandable views, but if we attempt to view this through a lens of austere morality, we have an awfully foggy perspective.