The People Like Capital Punishment?

I found the following figures to be quite alarming. With more and more studies showing a high percentage of people on death row are wrongly convicted, I would think the blood lust for capital punishment wouldn't be so high. I'm not sure if I'm against the death penalty, but what I do know is it cost the government more to kill a man than it does to keep him in prison for life. I also know that lethal injections are not preformed by doctors on ethical grounds, raising the risk of complications during the execution. With the current practice of state execution I would think many people would want to take a hard look at the situation. I must have assumed wrong.