No justice system is perfect… but a system that kills people is more imperfect than any other. A system of justice that kills people is arrogant beyond belief: it tells the population that we are so overwhelmingly arrogant that we never make mistakes that we are willing to take utterly irrevocable action and kill people we think deserve it.
Such a system ignores the merest possibility that people are fallible – we all make mistakes! Also evidence can be just wrong, and people can be convicted of crimes they did not commit: and with the death penalty that means they will be killed by the state even when they are innocent.
So: the only people allowed to campaign in favour of the death penalty are those that have signed a legally binding form that states they are willing to be killed by mistake for a crime they did not commit… So: anyone you meet who is in favour of capital punishment ask them this question: “Would YOU be willing to be executed by mistake?” If not then they are hypocrites who are unwilling to face the consequences of their actions and they really have not thought out the implications of what capital punishment means.