The great legal scholar Richard Posner once famously asked, “What do judges maximize?” Given all the publicity surrounding the “not guilty” verdict in the trial of George Zimmerman for the murder of Trayvon Martin, I would ask a different question, What do juries maximize? Jurors have not studied the law and are not compensated the full market value of their time, and yet, in most cases, they seem to get it right. Put another way, why don’t jurors behave like self-serving bureaucrats or politicians? Could it be that more altruistic and civic-minded persons self-select into juries? What do you think?
prior probability 
Well they definitely did not get it right in the Zimmerman or Casey Anthoney cases!
That is a very good point. Also, how can we say that a particular verdict is “right” or “wrong” when there is no way of verifying the truth of the evidence submitted to the jury? That is, what criteria do we use in judging the accuracy of a jury verdict? Instead, I would argue that most verdicts are “probabilistic” in nature: jurors believe with some degree of probability in the accuracy of their verdict. It would thus be an interesting experiment if jurors were allowed to express the strength of their beliefs in their verdicts from 0 to 1 …