We should not bring back the death penalty. The practice is a disgraceful one that should be left firmly in the past, as we progress into a century where human rights should be respected; the implementation of the death penalty is fraught with dangers that simply cannot be resolved at the current moment.
Firstly, there is a fundamental disagreement between the state's pronouncement to protect the right to life and its willingness to take it. A state that has the highest degree of respect for life cannot transmit that same respect to its people if the state itself is willing to take a life when it sees fit. Along with the death penalty comes cases where we are not confident about the guilt of the person, or new evidence comes out later. If you execute someone then these mistakes are irreparable. The state oversteps the line if it takes the life of its citizens if it sees fit, because its duty to protect the citizens is not changed if it chooses life imprisonment over the death penalty. It endangers more lives of innocent citizens by applying the death penalty (which is accorded by fallible humans) than if it does not impose the death penalty.
Secondly, the application of the death penalty is inconsistent; whether you receive it depends on facts beyond those pertaining to the crime. Because we agree that blanket application of capital punishment is inhumane, we must allow humans to make the decisions on when to apply the death penalty and not, but this means that human prejudices are effectively deciding whether somebody lives or dies. Amnesty International discovered that, in the US, "blacks convicted of killing whites were sentenced to death fifteen times more often than whites convicted of killing blacks." Yes, prejudices are impossible to completely remove, but they should not be allowed to influence a decision as fundamental as whether somebody should live or die.
Thirdly, the numbers of errors in the system is too substantial a proportion of the total to be allowed. A comprehensive study of capital punishment cases in the US found that 7% of those on death row were found to be "demonstrably innocent". Not only does such an error rate lead to the risk of innocent people being put to death, but it also means that those who have been found innocent on death row have been subjected to inhuman treatment. I am sure that those who support the death penalty will agree that no innocent person should have to spend years in a state of confinement, without the rights usually given to prisoners, having to mentally grapple with the judgement that their life will be ended because of an act that they did not commit. Your perceived "revenge" cannot atone for that imperious sense of impending death which mentally tortures innocent people on death row, who know not whether they will live or die.
Fourthly, the actual killing is prone to error and can involve inhumane treatment in an unacceptable number of cases. As we believe that a person should be told when they are going to die (and not shot in the dark), we have to live with cases of them suffering in animal-like agony, and with botched attempts. In the past few years, states in the US have suspended executions because studies have suggested that the preferred method of lethal injection is cruel and painful. People find beheadings disgusting to their nature; hangings often result in excruciating deaths; the electric chair was prone to error, with witnesses horrifically watching blood coming out of the prisoner's eyeballs. The US is slowly realizing that none of the methods of capital punishment are ones that it is willing to inflict on other people.
Lastly, economically the death penalty is far more expensive to implement correctly, even when the quality of that implementation leaves much to be desired. For example, according to The Economist, each death penalty case costs $2m more than one where the guilty party is sentenced to life imprisonment. Those who support the death penalty have to answer for this greater expenditure, and why they think it is worth spending millions more to attain what they see as "revenge". I submit that even if we put aside the moral arguments, the death penalty is a wasteful use of money.
Let's be civilized; let's respect our human rights. Do not support capital punishment.
K.