I still can't quite understand why capital punishment is an issue in the first place. It's like the Ebola of the justice system: we can document it has killed someone in the last year, but the number of lives it has claimed is fewer than die of stupid things like lightning strikes. I'm being serious too! There were 39 executions in 2013 and about 73 people a year die of lightning strike. Meanwhile you have some 2.4 million people dying in USA every year and about half of those are considered to be premature in some way, usually from cancern, heart disease, or other big ones. Accidents take 100,000, murders take another 20,000.
But executions? Really? That's like saying that Ebola is something that you need to worry about in America. The argument of people being executed for false crimes is even more astonishing, as it's nearly impossible to get somebody executed in the first place, but even if it's 1%, that would mean that only 1 out of every 3 years would have one single American executed who was innocent of the crime for which they were convicted. Again, 1 death in 3 years is pretty minimal compared to cancer, alcoholism, accidents, murders, and so on.
If we really cared so much about saving lives we would be restricting the purchase and production of alcohol, cigarettes, fatty foods, and high risk activities that commonly result in death: I'm looking at you, motorcycles.
But alas, nobody really cares about capital punishment because 39 people a year, at least 99% of whom were absolutely guilty, is a tiny number. It's just a political football that gets kicked around for show in order to distract from all the aforementioned REAL killers like cigarettes, fatty foods, etc. Since nobody wants to do anything about all the preventable deaths of all those other types, they talk about strawman arguments instead.