Capitla punishment is justifiable as a deterence because it is the final punishment.
Anyone who takes another persons life obviously does not care about their own life or are just too mentally unstable to realize the impact of their actions. Capital punishment allows society to feel safer because otherwise there is a chance that more and more innocent people's lives could be in danger. If capital punishment did not exist all of the serial killers such as Dahmer and etc. would still be sitting in prison and may have the opportunity to escape. Then once again, society is put in jeopardy. I think that that any person who committs a heinous crime, such as murder, should have their life taken away from them.