Sorry, I forgot that for a moment as we don't have death penalty in Germany, but you're right. Is somebody familiar with South Korean law? Do they take mental illnesses into account?
Nevertheless there would be a proper trial, wouldn't it? Hence it is possible for Sangwoo to reflect his actions in front of a court...possibly. I just don't feel at ease with someone dying like this.

Honestly, I can't agree with everyone claiming Sangwoo deserves death. No one does, especially not this kind of painfull death. Yes, he is a murderer, but I'd rather see him getting punished by a judge and going in jail and most important in therapy, reflecting his actions and dealing with his past.