Colin G. Tredoux’s research while affiliated with University of Cape Town and other places

Identification parades are essential when obtaining evidence of identity from eyewitnesses. Eyewitnesses are shown a line of people containing the suspect(s) and innocent fillers, and witnesses are asked to point out the perpetrator(s) of the crime, noting that the perpetrator(s) might not be present. Corporeal (‘live’) parades are required in South Africa unless there is a good reason not to use them, in which case the police may use photograph parades. We review the rules for conducting parades in South Africa and compare these to those in several other countries, many of which no longer use corporeal parades. We consider evidence from empirical studies that have tested the ‘live superiority’ hypothesis and conclude that there is no clear evidence in its favour, notwithstanding that there are benefits to augmenting static views of faces with additional cues to identity. We then consider the logistical and financial cost of conducting live parades, which we find to be considerable. We conclude that it may well be time to reconsider the use of live identification parades in South Africa but caution that this should coincide with a review of the law regulating the use of alternative methods to ensure that accused persons receive fair trials.

Objective: The risk of mistaken identification for innocent suspects in lineups can be estimated by correcting the overall error rate by the number of people in the lineup. We compared this nominal size correction to a new effective size correction, which adjusts the error rate for the number of plausible lineup members. Hypotheses: We hypothesized that (a) increasing lineup bias would increase misidentifications of a designated innocent suspect; (b) with the effective size correction, increasing lineup bias would also increase the estimate of innocent-suspect misidentifications; and (c) with the nominal size correction, lineup bias would have no effect on the estimate of innocent-suspect misidentifications. Method: In a reanalysis of previous literature, we obtained 10 data sets from Open Science Framework. In three new experiments (Ns = 686, 405, and 1,531, respectively), participants observed a staged crime and completed a fair or biased lineup. Results: In the reanalysis of previous literature, less than four of six lineup members were identified frequently enough to be classified as plausible, M = 3.78, 95% confidence interval [CI: 2.20, 5.36]. In the new experiments, increasing lineup bias increased mistaken identifications of a designated innocent suspect, odds ratio (OR) = 5.50, 95% CI [2.77, 10.95] and also increased the effective size-corrected estimate of innocent-suspect misidentifications, OR = 3.04, 95% CI [2.13, 4.33]. With the nominal size correction, lineup bias had no effect on the estimate of innocent-suspect misidentifications, OR = 0.84, 95% CI [0.60, 1.18]. Conclusions: Most lineups include a combination of plausible and implausible lineup members. Contrary to the nominal size correction, which ignores implausible lineup members, the effective size correction is sensitive to implausible lineup members and accounts for lineup bias when estimating the risk of innocent suspect misidentifications.

Court instructions and public perception endorse that eyewitness evidence provided by police should weight more heavily than laypeople's in court. Evidence is inconsistent. The current experiment provides a nuanced analysis of identification performance of police and laypeople at different levels of confidence. Laypeople and advanced police trainees ( N = 192) viewed portrait, profile, and body‐only lineups for central and peripheral targets. Police trainees displayed higher hit and correct rejection rates than laypeople for portrait lineups, and higher correct rejection rates in profile lineups for central targets. Calibration was similar for both groups, although police trainees had an advantage at low target presence base rates. Calibration was best for central targets' portrait and profile lineups. Participants displayed poor calibration and strong overconfidence for body‐only lineups and peripheral target lineups. We conclude that experience and specialization of police might be important when investigating a possible superiority of police who serve as eyewitness.

The own‐group recognition bias (OGRB) has been consistently linked to social contact in theoretical accounts. Indeed, social contact is assumed by most authors to underlie the perceptual expertise of out‐groups' faces. However, little is known empirically about how it might impact face‐processing strategies. We tested the proposition that social interaction would improve the face recognition performance of another group by modulating visual strategies for different face areas. In Experiment 1, we studied visual processes using an eye tracker during a person's first live encounter with a particular member of their own group (European) or an outgroup (African) to explore how increasing familiarity during a first interaction influences face‐processing strategies. In Experiments 2 and 3, we explored the effect of simulated intergroup contact on face recognition accuracy, while simultaneously studying the impact of contact on visual attention strategies that occur during recognition (Experiment 2) and encoding (Experiment 3). The results showed a strong OGRB and a difference in visual processes based on the ethnic group of the targets. Although a single interaction is not sufficient to reduce the OGRB, familiarization during a live interaction (Experiment 1) and virtual social contact (Experiment 2) had an impact on the visual strategies employed.

Identifying a suspect is critical for successful criminal investigations. Research focused on two decision processes during lineup identification, namely ‘automatic recognition’ and ‘elimination’ strategy, and their relation to identification accuracy. In this article, we report two experiments conducted in France and South Africa, which further examine strategies in eyewitness decision-making. We first used a modified-RSA (Retrospective Self Awareness; Kassin, 1985) interview method to construct questionnaires to have finer-grained measures of cognitive processes involved in lineup identification. Studies 1 and 2 tested the relevance of the questionnaire in each of the countries, and factor analysis yielded three common factors among the countries, namely the expected ‘automatic recognition’, and ‘elimination’ strategies, as well as an additional familiarity related factor. Logistic regressions showed that witnesses who reported using a familiarity feeling and/or an ‘elimination strategy’ to conduct their decision, were less likely to make correct decisions than witnesses who reported using ‘automatic recognition’.