With the release of the Obama administration's targeted killing white paper, state-enacted violence is getting attention in the news; however, rather than focusing on that incidence of state-enacted violence, I would like to focus on another one: capital punishment.
Perhaps the most common moral argument (besides the "sanctity of human life" argument) against capital punishment is what I would call the argument from uncertainty. In other words, new evidence may appear in the future that can vindicate the individual; it would be heinous to use the enforce the highest form of punishment on someone who was, in fact, innocent. Under the Constitution through its inheritance of common law, individuals are innocent until proven guilty, and if one is going to seek to end a life, the burden of proof must be prohibitively high.
Moreover, capital punishment cannot be upheld through an argument from self-defense. The crime in question is past and cannot be undone; consequently, there is no role of self-defense for that specific case. Self-defense projected onto the future, or "preemptive action," falls into the same realm of uncertainty. We cannot know that such a person would commit another such crime in the future; as mere mortals, we are not blessed with such foresight.
However, one moral argument against capital punishment that is often overlooked is the one that does not focus on the convict but on the executor. Under a system of capital punishment, the state is paying someone to kill--to pull the switch for an electric chair, to administer poison.
Now, police officers, in the name of public safety, might have to kill someone in order to protect another life--a vicarious self-defense, if you will. However, the act of killing is only incidental, not essential, to the job of the police officer. The first and foremost duty of the police officer is public safety and public protection.
However, the job of the executioner is to kill; the taking of human life is essential to his duty, not incidental. And that I find to be most morally troubling. The state is paying this individual to place his moral senses on hold and to take another human life in an act that cannot be construed as self-defense. What effect must this have on that individual's moral compass? Frederick Douglass wrote about how slavery was damaging to the humanity and dignity not only of the slave but also of the master, and a system of capital punishment likewise threatens the dignity and humanity of the individual paid to execute another in cold blood.