I dont necessarily have a moral problem with the concept of a death penalty.
I do have a problem...with that penalty being imposed by the state under our current system of criminal justice. The reality is that, if you are white and wealthy, that penalty will likely never be imposed upon you.
I am also a person of faith, and a believer in karma. So a sentence of "life with no parole" to me is nothing more than a delayed-action death sentence. It doesnt matter to me whether the criminal dies in the execution chamber today or in a prison hospital in 20, 30 or 40 years. Either way they have been removed from society, and they will ultimately be judged by a being who is far more capable of administering true justice than we as a society will ever be.
My opinion is that the role of our criminal justice system should be to (a) rehabilitate those who can be rehabilitated and (b) protect society from those who cannot. Issues like vengeance and retribution and punishment are best left to the supreme wisdom of a power greater than ourselves.