It is hard to tell if capital punishment has such an effect. And even if, in some contexts it has (such as in the American South with a very high incidence of murder), this effect may very well go away if a decent welfare state was replaced for the existing social order.

Utilitarianism condones killing of innocent human beings, even murder, if it makes the world a better place.

How could it be that I had a legal obligation to kill people I did not know, and who did certainly not consent to it, while my father's doctor could not help my father to die when my farther asked for it? My consternation brought me to moral philosophy and a life-long search for an answer to the question when and why we should, and when we shouldn't, kill.

There comes a time where next to everyone will resort to techniques that enhance cognitive, mental including emotive, physical, and other capacities. When this has happened, if not before, the ban on doping in sport will have been lifted.

My conjecture is that most people will refuse to let go, even when their lives have become boring (at least in comparisons with possible lives lived by new generations). If this happens, there will eventually be no room for new generations. A kind of collective irrationality will lead to a bleak life for the last generation that decides to stay around. Unless we put and end to the human race (through global warming, for example), before this happens, individual egoism will block the path to a better world.

I want to think that there are better ways of obviating murder than to resort to capital punishment, but I realise that this may be wishful thinking on my part.

According to deontology it is wrong to kill an innocent human being, period.