Becoming a murderer is too often celebrated. For many it's an initiation or a rite of passage with little or no consequence.
The fear of a gruesome public exit from society and from life itself might serve them and society better than our current leniency and tolerance.
Actually all we really need is a return to “speedy trials”. Wasting years to even get to trial is asinine. And then, speedy punishment. Death penalty loses its sting when you have decades before the axe falls. Nevermind all the chances for appeal and escape in that time.