I’m anti-death penalty but I often enough find myself playing devil’s advocate in situations like this just because I tend to find the arguments employed by my fellow anti-DP advocates to be very poor. Personally my favorite argument against the death penalty is the fact that it’s in violation of the basic morality that serves as the framework for the very laws we execute people for violating.
The argument that “this person was no threat to society” is a poor one. It implies that the criminal justice system exists purely to keep threats to society at bay, this is not true. The criminal justice system has other extremely important goals. One of them is settling matters equitably. Before the establishment of formalized criminal justice systems if someone killed a friend of mine, I’d get together 6-7 friends of mine (or more) we’d march down to his house and kill him. It was mob justice.
As civilization advanced mob justice was recognized as poor, there was no guarantee that the person the mob punished was guilty, and there was no restraint of the power of the mob. Furthermore, there was no guarantee that the mob was going to punish someone in a manner fitting his crime.
The government usurped this process for the public good. Now, if you are accused of a crime the government puts you through a fact-finding process, it must be proven beyond a reasonable doubt that you committed the crime before you can be punished for it. During this fact-finding “trial” process you have constitutional rights that cannot be violated, you are entitled certain rights that help to give you a very good chance of proving your innocence if you are indeed innocent.
To move it back to my point, part of the criminal justice system is indeed all about protecting society at large. Part of it (a huge part of it) however, is about providing the vacuous concept of “justice.” The people are seen as being entitled to justice. When I kill, rape, maim, steal, et cetera I’ve both committed a crime against another person and against society at large. I’ve “wronged” society. Just like in a civil case, if I wrong someone, I have to pay for it. I have to pay some monetary fee. In a criminal case, the wrong I committed is often seen as being great enough that a simple monetary compensation will not provide an equitable result to either society or the victims of the crime I committed. In some cases, society has seen fit to implement executions to right the most ultimate of wrongs. Personally I disagree with that, but again I’m playing DA here.
Let’s use an example. Imagine that Tom & Jerry, instead of being cat and mouse, were two human beings. Tom had a deep hatred for Jerry, they were arch-enemies. One day, after many years of trying, Tom successfully killed Jerry. Tom is sent to prison for 20 years to life. Under your “protecting society” concept Tom shouldn’t serve a day in prison. He killed Jerry because Jerry was his arch-nemesis, you only have ONE arch-nemesis. Tom could reasonably and logically explain that he killed Jerry because Jerry was his arch-nemesis, that he doesn’t have any other arch-nemesis and thus there’s not reasonable risk that he’ll ever murder someone again.
To accept Tom’s argument would be to say that society, and Jerry, don’t deserve anything in return for the grave wrong that Tom committed against them. And that, goes against the very foundations of the criminal justice system.