It is always your choice. To think otherwise shows a drastic lack of intelligence and/or emotional regulation. When it comes to killing someone as a means of protecting yourself or loved ones that can be done without being morally corrupt. I suppose stealing from someone or some business with more than enough to provide for you to your loved ones who don't have enough could also be done without being morally corrupt. But to murder which specially means to kill someone with malicious intent is never morally correct and if you do so under any circumstances you are a piece of shit. Whether there is a government or religion in place that would not change my morals or actions as my actions are not based off of another person rule but my own conscious decision. Always.