I support the death penalty for first degree murder, and any killing that is done while committing a felony. I would also personally like to see it extended to child molesters.
The key reason I support capital punishment has to do with the comfort and well being of the victim's family members. Once a family loses a loved once to senseless violence, they no doubt experience an enormous amount of pain and suffering. Knowing that their killer will face a capital murder charge, helps ease the pain somewhat.
Doesn't that assume that every victim wants lethal revenge?