Measuring lineup fairness

Abstract

SUMMARY The fairness of line-ups and photospreads is a traditional concern of research and policy development in the area of eyewitness identification. Quantification of fairness, the construction of fairness indices, and the development of evaluation procedures started in the 1970s and continues to this day. This paper reviews the historical development of the field as an introduction to the articles that follow. The entire set of articles addresses current questions and raises new issues of measuring the fairness of identification procedures. Copyright # 1999 John Wiley & Sons, Ltd. The literature on the measurement of line-up fairness began with the report by Doob and Kirschenbaum (1973) of their attempt to measure the bias contained in an identification process brought to their attention by a defence attorney. The verbal description of the oAender was extremely vague. She stated only that the criminal was ‘rather good looking’. The possibility existed that the witness had simply chosen the best-looking person from the line-up, whether he was the oAender or not. To test this conjecture, Doob and Kirschenbaum gave the description of the criminal and a photograph of the line-up to a set of persons who had never seen the criminal. They were asked to choose the suspect from the line-up. If these ‘mock witnesses’ (Wells et al., 1979) were able to identify the suspect, never having seen him but solely on the basis of the verbal description, the line-up could be considered biased in the sense that the alternative line-up members were not full (eAective, functional) alternatives to the suspect. The underlying assumption of Doob and Kirschenbaum’s method was that the alternatives (distractors, fillers, or foils) in a line-up ought to protect innocent suspects from identifications based solely on their match to the witness’s description of the criminal (recall). Instead, the witness should have to rely on the presumably more informative data provided by recognition of the face as a match of the suspect’s appearance to the witness’ memory image derived from having witnessed the original event (Wells, 1993). Thus line-up foils ought to be plausible choice alternatives: the suspect should not stand out in comparison to them. The reductio ad absurdum would be to place a suspect described as a European‐American in a line-up with an African‐American, an Asian‐American, an elephant, and a refrigerator. Doob and Kirschenbaum’s (1973) procedure oAered an attractive paradigm for post hoc evaluation of fairness in line-ups and photospreads, through the use of the