Murder requires premeditation, so that precludes self defense. The two parts are: The killing of someone without legal justification (such as self defense), and

Murder requires premeditation, so that precludes self defense. The two parts are: The killing of someone without legal justification (such as self defense), and the premeditated plan to accomplish it. There is something called "mens rea," the guilty mindset, that informs the court of guilt or innocence. This will get you into manslaughter and other shades or degrees of killing, too. The rest of what you said, I generally agree with. If you believe someone with a mental condition can sometimes "come around," then you'd also have to believe that someone who killed because of a DSM-5 defined condition that lists it as a symptom or hallmark can be cured of the triggers that made them do it. But I'm sure in most cases that privilege has to be long fought for. I always thought the Biblical command should have been "Thou shalt not murder" since it is absolutely possible to kill without even a trace of mens rea. Auto accidents are a good example. And war killing in the Bible, as in modern life, isn't considered murder either (Geneva Convention subjects aside). There is legal justification.