@Lash Goth,
Absolutely against it for Ethical Moral and Philosophical and Scientific reasons.
The strongest argument against it, one that sustain other weaker arguments, is the absence of free will. Won't debate why I believe it is true, but this is my main focus on the topic.
It follows that from not believing in Free Will my all approach to the problem of Good and Evil had to change, thus I prefer to talk about, balanced vs unbalanced people, or emotionally disturbed people, urges, compulsions, self narrative confabulation when it comes to open intention of doing "evil"...etc etc.
My whole approach to the problem of Evil is in essence not difference to my whole approach to weather and a perfect storm...
...moreover the whole topic of pain and suffering, the topic of precarious equilibrium, and the topic of fitness in natural selection, intertwine to explain why "evil" exists and has a NATURAL place on the ecosystem in very precise measures so to make it work...
On the opposite end of the spectrum a perfect equilibrium would have resulted in a perfect distribution of energy on the Cosmos and no complex patterns would exist.
So in sum no I am not in favour of death penalty although I agree mentally disturbed and unbalanced people need to be locked up sometimes for life.
Not because they are at fault but because they represent a risk to society.
The very ecosystem that allows them to exist and not be extinct by natural selection, is the same who locks them up in order to keep the ratios of "extremely harmful predators" or psychopaths in colourful language, below the 3% margin...those are the ones who do not get caught and keep society alert and smart.
