Okay, well I might as well put forward my own argument. Although you are able to justify the use of the death penalty in theory, when put into practice, it can cause lots of problems. For example, if someone is wrongly accused of a serious crime, they can be put to death even if innocent, which is of course unfair. Another big issue with the death penalty is that it gives the state the power to put its own citizens to death, and in my opinion, the state shouldn't be given that much power over its citizens. A much better alternative to the death penalty is prison, where actual criminals can be rehabilitated, and if someone is wrongly accused, they can be freed after being proven innocent.