Who should stand next to the suspect? Problems in the assessment of lineup fairness.

Abstract

A common procedure for assessing the fairness of a lineup is to give a verbal description of the perpetrator to people who did not witness the incident and ask them to select the likely perpetrator from the lineup. If people who never saw the perpetrator nonetheless make the right choice significantly more often than chance, the implication is that the lineup is unfairly suggestive. Little is known, however, about the factors that might bias this mock witness procedure. Two such biasing factors were examined in this study: the arrangement of photos in the lineup and the diagnosticity of the description. The results suggest that placing the target between 2 low-similarity foils increased the likelihood that he would be chosen, but only when the verbal description contained few diagnostic features. Implications for applied researchers and the construction of lineups are discussed.