I would wager most killings are retribution for some kind of wrong, simply by people who don’t believe in the justice system or whose rage overwhelms their fear

I would wager most killings are retribution for some kind of wrong, simply by people who don’t believe in the justice system or whose rage overwhelms their fear of consequences. If murder were legal then that would be a blow to state legitimacy and also remove much of the reason not to take matters into your own hands.