This essay discusses both the highly publicized extraordinary miscarriages of justice and unfortunately the much too frequent ordinary variety. It begins with the Duke Lacrosse and Central Park Jogger cases, which were extraordinary. Sometimes in cases of both varieties outrageous ethical errors by prosecutors were at the core of the injustice, but more frequently the prosecution error was in quickly reaching an expected result relying on apparently persuasive but questionable sources of evidence. The cases often involve the use of informants who received substantial benefits for testimony that incriminates the defendant and scientific evidence that did not actually establish what it appeared to prove. Another type of scientific evidence - exonerating DNA evidence - typically rectified the error, apparently promising clear answers to questions of innocence. Unfortunately, such certainty is often missing in problematic cases. Indeed, scientific evidence may give us the false sense of an ability to determine clearly when errors have been made and divert attention from the often inherent impossibility of knowing whether justice has been done.
To be sure major ethical failures by prosecutors do occur, but the message of this essay is that they are not central to erroneous convictions. Instead, the more common and persistent problem lies in institutional weaknesses that give prosecutors a narrow focus to their task as it relates to the innocent. The key relevant ethical command is that the prosecutor “do justice,” which is sometimes explicitly violated or callously ignored but is more commonly given insufficient attention. As a result, the essential problem common to these cases is not likely to be rectified by the creation or enforcement of ethical commands. Instead, critical reforms are likely to appear mundane and to be forward-looking rather than attention-grabbing and remedial. They entail institutional redesign and the implementation of standard practices, such as broad discovery, which may appear far removed from lofty pronouncements in ethical rules.