As the loved one of a murdered person, I can speak to this. Nothing will bring back my loved one. Nothing. Gone forever. A hole left unfilled for eternity. Executing her killer won't bring her back. It won't help anyone "heal" or "find solace" or any other words that politicians use.

> Killing them feels much more like payback

I'm sure many find that it didn't feel like it at all, because of my argumentation. Payback will always be incomplete. It can never be paid in full.

Even if you kill someone over and over again (some Sci-Fi comes to mind), the perp always took the first step and elevated his role in society unjustly.

Lack of punishment can lead to more crime if people lose faith in the system. To take it to an extreme, if murder were punished with only a fine then victim families would just hire assassins to kill off a murderer if they feel the fine doesn’t suffice.