My stance has never changed since ever, no one should be executed UNTIL the system proves to run perfectly. How can you prove that? Really, you can't prove because many of facts or information within judicial system often withheld from the public, often they were sealed in some form. Because of hidden information exists, how could we trust those people doing their job properly?
Have you seen transcriptions from any Juror deliberations? What have they discussed about? Were they being honest with their own decision? Were they eager just to get the case close and move on that could result wrong verdict? No one outside of that deliberation room knows exact whats happened inside. That is why its impossible to get fact out except the verdicts.