Years ago, people in favor of the Death Penalty used to dismiss claims that innocent people are sometimes executed. It struck me that their certainty was some combination of wishful thinking and stubborn denial.
It's getting harder and harder to take that position, especially with DNA testing now proving how many people have been wrongly convicted of serious crimes. This latest case doesn't involve DNA but there's still some pretty solid evidence that an innocent man was executed in Texas in 2004. This is not to suggest, of course, that the government of Texas will ever admit it.
Thanks to Mark Thorson for sending me this link, and also for a lot of typos he's caught on this site. Between him, Gordon Kent and Rephah Berg, I don't need a spell-checker.