Is it deviance to kill certain people?

I recently read an article in the Chicago Tribune discussing how to approach the subject of Osama Bin Laden's death when talking to children. Many people celebrate Bin Laden's death, hailing it an important justice to both the people of America and the Middle East, and some t-shirt companies have even taken it upon themselves to create shirts just for the occasion. However, parents who just started teaching their children that it is not okay to hurt people are struggling to explain to their children the happiness and relief surrounding Bin Laden's death. Suddenly parents and teachers with children who just learned "thou shall not kill" are in a pickle trying to figure out a way to explain to them when it is and isn't okay to kill someone. Depending on one's point of view, killing Bin Laden may or may not be considered deviance. We live by the consensus that it is immoral to kill someone, but we also execute people who can't conform to our norms to an extreme. I still can't decide whether or not I think it should be considered deviant to kill or if one idea of deviance and morals can even be applicable to all situations, but I know for sure I'm at a loss for words on how to explain it to children.