Columbia Public Law & Legal Theory Working Papers

Document Type



Exonerations famously reveal that eyewitness identifications, confessions and other “direct” evidence can be false, though police and jurors greatly value them. Exonerations also reveal that “circumstantial” non-matches between culprit and defendant—e.g., a non-matching aspect of an eyewitness’s description or a loose button at a crime scene—can be telling. Although non-match clues seem uninteresting because they are easily explained away, they often turn out to match the real culprit when he or she is eventually caught. This article uses “non-exclusionary non-matches” and their seeming polar opposite, inculpatory DNA, to show that: (1) all evidence of identity derives its power from the aggregation of individually uninteresting matches or non-matches, but (2) our minds and criminal procedures conspire to hide this fact when they contemplate “direct” and some “circumstantial” evidence (e.g., fingerprints), making it seem stronger than it is , and to magnify the fact as to non-exclusionary non-matches, making them seem weaker than they are. We propose ways to use matches and non-matches more effectively to avoid miscarriages.

Date of Authorship for this Version

Winter 2-12-2012