I can say “YES” only because my religion says yes. However I know usually my words do not go easy on a few here and therefore I would explain.
First of all anyone who says “No” most of the times ends up saying yes when any of their own loved one is a victim. So it is invalid or a “NO” is simply due to no understanding of the impact one sufferes. Then fist and by far the most important factor is a flawless legal system where there should be no doubt whatsoever. Putting people in prison only make others suffer financially as well as emotionally and the person in the prison usually has a 5 star treatment in a prison where he would have luxuries that many of us would not be able to afford. Then a few people said that it does not detter anyone. So first of all how do we know? Then other problem is that most of the countries serve death penalty behind closed doors and obviously it would not detter many. Punishment should be public only then it serves the purpose.
Now I know that after my above statements many are itching to jump with words like barbaric, uncivilised and much more but finally I would tell you what Islam (my religion) really says about capital punishment for example in case of a murder. It is very clear that Islam gives relatives of the victim 3 choices. 1 – They can decide to have an eye for eye and get that person be killed as after all its they who lost a loved one, and especially where no regret is being shown by the culprit and he may do it again. 2 - They can receive blood money and forgive, that money may help them long way after the loss of a loved one who might just be the only bread winner for them. And on other hand if the accused is showing any regret or so. 3 – They can forgive without any money and in Quran Allah says that Allah loves people who forgive. However if the situation is a kind where forgiveness may be due to some force or influence and where the crime is not against one person but against a society then legal system does not allow forgiveness.