Roderick C. L. Lindsay

Simultaneous Lineups, Sequential Lineups, and Showups: Eyewitness Identification Decisions of Adults and Children

Two experiments were conducted comparing the identification accuracy of children aged 3–15 years (N = 307) and undergraduates (N = 384) using target-present and target-absent simultaneous and sequential lineups and showups. Correct identification rates tended not to vary across either age of subject or identification procedure. However, children show a significant tendency to guess as indicated by their lower rate of correct rejection when the target is absent. The tendency for children to make false positive choices was particularly evident with showups.

Elimination lineups : An improved identification procedure for child eyewitnesses

Elimination lineup procedures were proposed that required the witness to eliminate all but I lineup member before being asked if the remaining lineup member was the criminal. Elimination lineups were designed and tested with the aim of reducing false-positive choices by child eyewitnesses (n = 587 children. 10-14 years, M = 12 years; n = 185 adults). Elimination lineups decreased false-positive responding in children without significantly reducing correct identifications. Fast elimination lineups with modified instructions emphasizing the negative consequences of identifying an innocent person and explaining how to make an absolute judgment significantly decreased childrens false-positive rate to a level comparable with adults shown a simultaneous lineup. The potential benefits of elimination lineup procedures for child witnesses are discussed.

Postdictors of eyewitness errors: Can false identifications be diagnosed?

Eyewitness researchers have postdicted identification accuracy using witness confidence (S. L. Sporer, S. Penrod, D. Read, & B. Cutler, 1995), response latency (S. L. Sporer, 1993, 1994), and endorsement of statements consistent with using relative versus absolute judgment strategies (D. Dunning & L. B. Stern, 1994; R. C. L. Lindsay & K. Bellinger, 1999). All of these measures were collected from 321 introductory psychology students who had viewed a staged crime and completed a lineup identification task. Some participants received feedback after identification (G. L. Wells & A. L. Bradfield, 1998). Lineup fairness was also used as a postdictor of eyewitness accuracy. Discriminant function analysis indicated that 75.2% of choosers and 63.0% of nonchoosers were correctly classified. Decision time and lineup fairness were the best postdictors of accuracy. The implications for postdicting real eyewitness decisions are discussed.

How Variations in Distance Affect Eyewitness Reports and Identification Accuracy

Witnesses observe crimes at various distances and the courts have to interpret their testimony given the likely quality of witnesses’ views of events. We examined how accurately witnesses judged the distance between themselves and a target person, and how distance affected description accuracy, choosing behavior, and identification test accuracy. Over 1,300 participants were approached during normal daily activities, and asked to observe a target person at one of a number of possible distances. Under a Perception, Immediate Memory, or Delayed Memory condition, witnesses provided a brief description of the target, estimated the distance to the target, and then examined a 6-person target-present or target-absent lineup to see if they could identify the target. Errors in distance judgments were often substantial. Description accuracy was mediocre and did not vary systematically with distance. Identification choosing rates were not affected by distance, but decision accuracy declined with distance. Contrary to previous research, a 15-m viewing distance was not critical for discriminating accurate from inaccurate decisions.

Impact of disguise on identification decisions and confidence with simultaneous and sequential lineups.

Prior research indicates that disguise negatively affects lineup identifications, but the mechanisms by which disguise works have not been explored, and different disguises have not been compared. In two experiments (Ns = 87 and 91) we manipulated degree of coverage by two different types of disguise: a stocking mask or sunglasses and toque (i.e., knitted hat). Participants viewed mock-crime videos followed by simultaneous or sequential lineups. Disguise and lineup type did not interact. In support of the view that disguise prevents encoding, identification accuracy generally decreased with degree of disguise. For the stocking disguise, however, full and 2/3 coverage led to approximately the same rate of correct identifications--which suggests that disrupting encoding of specific features may be as detrimental as disrupting a whole face. Accuracy was most affected by sunglasses and we discuss the role metacognitions may have played. Lineup selections decreased more slowly than accuracy as coverage by disguise increased, indicating witnesses are insensitive to the effect of encoding conditions on accuracy. We also explored the impact of disguise and lineup type on witnesses confidence in their lineup decisions, though the results were not straightforward.

Are multiple-trial experiments appropriate for eyewitness identification studies? Accuracy, choosing, and confidence across trials

Eyewitness identification experiments typically involve a single trial: A participant views an event and subsequently makes a lineup decision. As compared to this single-trial paradigm, multiple-trial designs are more efficient, but significantly reduce ecological validity and may affect the strategies that participants use to make lineup decisions. We examined the effects of a number of forensically relevant variables (i.e., memory strength, type of disguise, degree of disguise, and lineup type) on eyewitness accuracy, choosing, and confidence across 12 target-present and 12 target-absent lineup trials (Nu2009=u2009349; 8,376 lineup decisions). The rates of correct rejections and choosing (across both target-present and target-absent lineups) did not vary across the 24 trials, as reflected by main effects or interactions with trial number. Trial number had a significant but trivial quadratic effect on correct identifications (ORu2009=u20090.99) and interacted significantly, but again trivially, with disguise type (ORu2009=u20091.00). Trial number did not significantly influence participants’ confidence in correct identifications, confidence in correct rejections, or confidence in target-absent selections. Thus, multiple-trial designs appear to have minimal effects on eyewitness accuracy, choosing, and confidence. Researchers should thus consider using multiple-trial designs for conducting eyewitness identification experiments.