I think that death penalty does not work the pain. In instead of that, all the prisoners should work and stay on prison for the rest of their lifes. The death penalty should be a choice. For example, I'm sure that a prison must be horrible. Who wants to live there forever? That's a choice... The prisoner will choose between live there suffering or die.
But the death penalty should exist just for extreme causes, like serial killers and others.
The reason why I don't agree with the idea of the death penalty is that because sometimes the persons have a problem and there are other times that an innocent person dies and the culprit is anywhere, not in prison.
We don't even have to chance to repent, because there isn't an option. Only the death.