Abstract

In theory a lineup is fair, from the perspective of the suspect, to the extent that the suspect is not distinctive in appearance from the other lineup members (foils) and all of the foils are reasonably similar in general appearance to the suspect. Lineup fairness can be divided into two dimensions-size and bias. Several proposed methods for empirically evaluating lineup fairness were assessed in terms of their sensitivity to absolute standards of lineup fairness and their discriminability, the extent that they differentiated between lineups designed to be fair and those constructed via less rigorous selection procedures. One of three lineup size measures and both measures of lineup bias showed significant discriminability. The sensitivity of the measures depended on the criteria arbitrarily chosen or, when using statistical significance, on sample size. Race of mock witness had some impact on evaluations of Black lineups but not on evaluations of White lineups. Results indicated that a sample size of 18 mock witnesses appears adequate for obtaining reliable and appropriately sensitive measures of lineup fairness. The functional size measure of fairness appears to have the most satisfactory degree of sensitivity and discriminability. Analyses of the fairness of lineups used in six actual criminal cases are also presented.