Eyewitness Evidence Improving Its Probative Value

Psychological Science in the Public Interest 11/2006; 7(2). DOI: 10.1111/j.1529-1006.2006.00027.x


The criminal justice system relies heavily on eyewitnesses to determine the facts surrounding criminal events. Eyewitnesses may identify culprits, recall conversations, or remember other details. An eyewitness who has no motive to lie is a powerful form of evidence for jurors, especially if the eyewitness appears to be highly confident about his or her recollection. In the absence of definitive proof to the contrary, the eyewitness's account is generally accepted by police, prosecutors, judges, and juries. However, the faith the legal system places in eyewitnesses has been shaken recently by the advent of forensic DNA testing. Given the right set of circumstances, forensic DNA testing can prove that a person who was convicted of a crime is, in fact, innocent. Analyses of DNA exoneration cases since 1992 reveal that mistaken eyewitness identification was involved in the vast majority of these convictions, accounting for more convictions of innocent people than all other factors combined. We review the latest figures on these DNA exonerations and explain why these cases can only be a small fraction of the mistaken identifications that are occurring. Decades before the advent of forensic DNA testing, psychologists were questioning the validity of eyewitness reports. Hugo Münsterberg's writings in the early part of the 20th century made a strong case for the involvement of psychological science in helping the legal system understand the vagaries of eyewitness testimony. But it was not until the mid- to late 1970s that psychologists began to conduct programmatic experiments aimed at understanding the extent of error and the variables that govern error when eyewitnesses give accounts of crimes they have witnessed. Many of the experiments conducted in the late 1970s and throughout the 1980s resulted in articles by psychologists that contained strong warnings to the legal system that eyewitness evidence was being overvalued by the justice system in the sense that its impact on triers of fact (e.g., juries) exceeded its probative (legal-proof) value. Another message of the research was that the validity of eyewitness reports depends a great deal on the procedures that are used to obtain those reports and that the legal system was not using the best procedures. Although defense attorneys seized on this nascent research as a tool for the defense, it was largely ignored or ridiculed by prosecutors, judges, and police until the mid 1990s, when forensic DNA testing began to uncover cases of convictions of innocent persons on the basis of mistaken eyewitness accounts. Recently, a number of jurisdictions in the United States have implemented procedural reforms based on psychological research, but psychological science has yet to have its fullest possible influence on how the justice system collects and interprets eyewitness evidence. The psychological processes leading to eyewitness error represent a confluence of memory and social-influence variables that interact in complex ways. These processes lend themselves to study using experimental methods. Psychological science is in a strong position to help the criminal justice system understand eyewitness accounts of criminal events and improve their accuracy. A subset of the variables that affect eyewitness accuracy fall into what researchers call system variables, which are variables that the criminal justice system has control over, such as how eyewitnesses are instructed before they view a lineup and methods of interviewing eyewitnesses. We review a number of system variables and describe how psychological scientists have translated them into procedures that can improve the probative value of eyewitness accounts. We also review estimator variables, variables that affect eyewitness accuracy but over which the system has no control, such as cross-race versus within-race identifications. We describe some concerns regarding external validity and generalization that naturally arise when moving from the laboratory to the real world. These include issues of base rates, multicollinearity, selection effects, subject populations, and psychological realism. For each of these concerns, we briefly note ways in which both theory and field data help make the case for generalization.
© 2006 Association for Psychological Science.

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    • "Composites with even higher naming (M = 45%) were produced when just internal features were shown, with external features added thereafter (Frowd et al., 2012d); for an example face array, see Fodarella et al. (2015b). A further important development was made by facilitating holistic processing prior to face construction (Frowd et al., 2012a): after witnesses have freely recalled a target using CI techniques (e.g., Wells et al., 2007), they reflect silently on its character for one minute and then make seven whole-face judgements—such as its level of perceived honesty or masculinity. These two whole-face techniques, when used after a face-recall CI, form the holistic-cognitive interview (H-CI). "
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    ABSTRACT: Purpose The article assesses the impact of seven variables that emerge from forensic research on facial-composite construction and naming using contemporary police systems: EvoFIT, Feature and Sketch. Design/methodology/approach The paper involves regression- and meta-analyses on composite-naming data from 23 studies that have followed procedures used by police practitioners for forensic face construction. The corpus for analyses contains 6464 individual naming responses from 1,069 participants in 41 experimental conditions. Findings The analyses reveal that composites constructed from the holistic EvoFIT system were over four-times more identifiable than composites from 'Feature' (E-FIT and PRO-fit) and Sketch systems; Sketch was somewhat more effective than Feature systems. EvoFIT was more effective when internal features were created before rather than after selecting hair and the other (blurred) external features. Adding questions about the global appearance of the face (as part of the Holistic-Cognitive Interview, H-CI) gives a valuable improvement in naming over the standard face-recall Cognitive Interview (CI) for all three system types tested. The analysis also confirmed that composites were considerably less effective when constructed from a long (1 - 2 day) compared with a short (0 - 3.5 hour) retention interval. Practical implications Variables were assessed that are of importance to forensic practitioners who construct composites with witnesses and victims of crime. Originality/value The main result is that EvoFIT using the internal-features method of construction is superior; an H-CI administered prior to face construction is also advantageous (cf. face-recall CI) for EvoFIT as well as for two further contrasting production systems.
    Journal of Forensic Practice 11/2015; 17(4):319-334. DOI:10.1108/JFP-08-2014-0025
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    • "We note two important limitations in the use of confidence to assess accuracy. First, the confidence–accuracy relationship is not as strong for negative responses (i.e., identifying no one) as it is for positive responses (i.e., identifying someone; Brewer & Wells, 2006; Sporer et al., 1995). The implication of the differing relationships for positive and negative responses is that lawyers, judges, and juries may be able to reliably distinguish between correct and false identifications based on witness confidence but may be much less able to distinguish between correct and false non-identifications based on witness confidence. "
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    ABSTRACT: This article addresses the problem of eyewitness identification errors that can lead to false convictions of the innocent and false acquittals of the guilty. At the heart of our analysis based on signal detection theory is the separation of diagnostic accuracy—the ability to discriminate between those who are guilty versus those who are innocent—from the consideration of the relative costs associated with different kinds of errors. Application of this theory suggests that current recommendations for reforms have conflated diagnostic accuracy with the evaluation of costs in such a way as to reduce the accuracy of identification evidence and the accuracy of adjudicative outcomes. Our framework points to a revision in recommended procedures and a framework for policy analysis.
    10/2015; 2(1):175-186. DOI:10.1177/2372732215602267
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    • "Over the years, slightly different variants of the Cognitive Interview have been adopted, but many of them involve the following stages (for review, see Memon et al., 2010): (a) rapport building between the interviewer and the witness; (b) context reinstatement: witness being asked to mentally reconstruct the context of the witnessed event; (c) report everything: witness being instructed to recall everything about the event; (d) change temporal order: witness being instructed to recall the event in a different temporal order, such as from the last event to the first; and (e) focused retrieval: witness being asked to expand on his or her description of recalled details. Many studies have shown that the Cognitive Interview is superior to a standard interview in increasing recall of correct information , but a few studies have also found that the Cognitive Interview is associated with a slight increase in the reporting of incorrect details (for a review, see Köhnken, Milne, Memon, & Bull, 1999; Wells et al., 2006). Despite the wealth of studies examining the effectiveness of the Cognitive Interview, relatively few have investigated the influence of this technique on older adults' recall (e.g., Dornburg & McDaniel, 2006; Holliday et al., 2012; McMahon, 2000; Mello & Fisher, 1996; Searcy, Bartlett, Memon, & Swanson, 2001; Wright & Holliday, 2007). "
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    ABSTRACT: In 2 experiments, younger and older adults witnessed a simulated robbery, received misleading information about the event, and then were interviewed with the Cognitive Interview about their memory for the robbery. In both experiments, older adults were disproportionately more confident than younger adults in the accuracy of incorrect information that they recalled than in the accuracy of correct information. Critically, this age-related increase in high-confidence errors occurred even in comparison with younger adults who were matched with older adults on the overall amount and accuracy of the information remembered about the robbery. In addition, Experiment 2 showed that retrieval warnings to disregard the misinformation were just as effective in older adults as compared with younger adults at reducing the reporting of misleading information. Finally, both experiments showed that across the multiple retrieval stages of the Cognitive Interview, the final retrieval stage is roughly half as effective for older adults relative to younger adults at eliciting previously unreported information. These results indicate that investigators have much less to gain from older adults than they do from younger adults with repeated inquiries (during the same session) about a witnessed event. (PsycINFO Database Record (c) 2014 APA, all rights reserved).
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