"Your moral compass is defined by the courts?"
Certainly not. My moral compass comes from the social mores of the world. In the USA, those are expressed in our laws. The definition I gave of murder is typical of that in our laws. I can find no real fault with it.
Perhaps you have a different definition. If so, let's see it.
Mine works pretty well. Murder is the ILLEGAL killing of another human being, with malice aforethought. That exempts things like killing in the military, or by a policeman, or in self defense. The malice part is important, too, since it is a definite part of the definition of murder.
If you kill someone illegally, but without any malice, as in a car accident while you were intoxicated, then it is manslaughter, not murder.
It's a pretty good definition of murder, IMO. It's the one I use as part of my personal code of conduct. Do you have any objections to it?