Prosecutors have a constitutional (and some might say moral) obligation to turn over potentially exculpatory evidence they might have or find to the defense in a criminal trial. The constitutional and moral obligation is premised on fundamental fairness, and the unique role of the prosecutor as both advocate and guardian of institutional legitimacy. Yet, under the “Brady” case articulating this obligation, even a failure to disclose potentially exculpatory evidence does not mean that a conviction will automatically be reversed – the defendant still has to show that the evidence could really have changed the outcome of the trial. Confused? So is the Supreme Court. The confusion is artfully explained in this article.