Your proposal to torture someone for a crime isn't one that I would agree with. Torturing someone just makes you the same as they are; dirty scum. Regardless if they have any guilt, that action of murder will come back to bite them in the ass and chances are it will be noted deep within their minds. I strongly believe that when a murder occurs, there will always be some guilt in the mind of those committed of it. Whether they show it or not, chances are they are suffering for their actions and to me that's good enough.
Now, I'm all for showing someone who they really are in a disgustingly vile way and would be glad to do it myself, but actually harming them in a form of torture is a bit much if you ask me. It's not something that you need to evoke physically, but mentally. That's where it is all occurring and that's where it's going to wake them up from their little dream of power and show them that they are scum. When a murderer finally recognizes and admits to themselves being scum, then that's where the job is complete and the guilt will finally enter.
Now, I use the term scum loosely. There's another word I have in mind, but that wouldn't be appropriate to be placing onto a Pokémon forum.