Double-blind photoarray administration as a safeguard against investigator bias.

Abstract

This experiment examined whether a photoarray administrator's knowledge of a suspect's identity increased false identification rates. Fifty participant-administrators (PAs) presented 50 participant-witnesses (PWs) two perpetrator-absent photoarrays following a live staged crime involving two perpetrators. For one photoarray per trial, the experimenter revealed the suspect's identity to the PA. Each PA presented the photoarrays sequentially or simultaneously in the presence or absence of an observer. When the observer was present, PA knowledge of the suspect's identity had a biasing effect in sequential photoarrays only. This pattern did not emerge when the observer was absent. The experimental manipulations did not affect PAs' and PWs' ratings of photoarray fairness or PWs' ratings of pressure to make an identification. These data suggest that only administrators who are blind to the suspect's identity should present sequential photoarrays.The vagaries of eyewitness identification are well-known... . A major factor contributing to the high incidence of miscarriage of justice from mistaken identification has been the degree of suggestion inherent in the manner in which the prosecution presents the suspect to witnesses for pretrial identification. . . . Suggestion can be created intentionally or unintentionally in many subtle ways.-Supreme Court Justice William Brennan, writing for the majority in United States v. Wade (1967) 940This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly.

Cognitive bias in line-up identifications: The impact of administrator knowledge

“…Given that, within the investigative domain, line-ups are typically administered by individuals involved in the case (frequently investigating officers), with a detailed knowledge of the contextual background to the identification [21], then there is certainly the potential for subjective biases to manifest and impact upon the identifications made [20,21,[26][27][28].…”

“…Phillips et al [27] give examples of a range of different types of cues that may be emitted, consisting of both verbal and non-verbal behaviours: In terms of verbal cues;…”

“…Thus, as Clark et al [26] observe, statements made by the lineup administrator which may seem on their literal surface to be cautionary, helpful, or encouraging, may in fact influence the witness's decision to make rather than not make an identification, and may impact upon the witness's choice as to whom to identify. Nonverbal cues that Phillips et al [27] identify include various facial gestures (e.g., smiling, frowning, or rolling the eyes) and body movements (e.g., nodding of the head, shaking the head back and forth, folding the arms, or leaning toward or even away from the witness).…”

“…target-present vs. target absent) or line-up presentation method (e.g. simultaneous vs. sequential exposure), may serve to strengthen or weaken susceptibility to, and resultant degree of, influence [27,28]. Now that the possibility of a fundamental administrator knowledge effect has been established, further research employing more complex versions of this research paradigm that take into account these various factors are certainly warranted.…”

“…As has been discussed throughout this article, eyewitness identifications and the lineup procedures through which they are obtained, are likely to be highly sensitive to administrator bias effects [20,21,[27][28][29][30].…”