Lineup Construction and Lineup Fairness

1. Introduction. Police lineups come from English criminal law and procedure. According to Devlin (1976), lineups were instituted through a Middlesex magistrate's order in the mid 19 th century. They were intended as a 'fair' replacement for the practices of courtroom identification, and showups, which were widely used in 19 th century England, but widely recognized as potentially unfair to the defendant. Their origin indicates that the notion of 'fairness' is their raison d'etre. They are intended to secure an identification that can potentially incriminate someone, but also is fair to those who are subjected to it, particularly those who are innocent of the crime. Study of the case law in many countries, as well as recent DNA-based exonerations in the U.S., indicates that lineups are not invariably fair – many innocent people are convicted after identification from a lineup by an eyewitness. The problem is significant because eyewitness evidence is cited as the most significant source of wrongful conviction (Scheck, Neufeld, & Dwyer, 2001). The DNA exoneration cases where the false conviction is established with near certainty show that eyewitness evidence has been largely responsible for false conviction in more than 70% of cases (www.innocenceproj.org). Wrongful identifications result from a number of failures of police procedure, however many of these are minimized when the lineups presented to witnesses are fair. If witnesses are induced to make a lineup identification, a fair lineup will expose the innocent suspect to an identification risk of 1/the number of persons in the lineup. A lineup biased against the