I'm opposed to the death penalty but I'm also opposed to arguing it's merits based on mercy. Bringing mercy into the discussion makes it subjective. Which criminals deserve mercy and which don't? Perhaps none do.

We should be opposed to capital punishment not because of the disposition of criminals (which we can never truly know) but because, as a society, we should be above vengeance. The only legitimate reason to execute criminals is to protect the innocent, and if that can be done by nonlethal means it should be. 

It's a mistake to get sentimental about murderers. Ricky Javon Gray was convicted for good reason and I hope he spends the rest of his life in prison. But he should be spared execution -- not so much for his sake but for ours.