A Lay Perspective on the Accuracy of Eyewitness Testimony1

To understand more about what laypeople think they “know” about eyewitness testimony, 276 jury-eligible university students were asked to indicate what factors they believe affect the accuracy of eyewitness testimony. In contrast to the large proportion of eyewitness-memory research that concerns system variables, the lay respondents overwhelmingly generated factors related to estimator variables, while system-variable factors such as police questioning and identification procedures were rarely mentioned. Respondents also reported that their own common sense and everyday life experiences were their most important sources of information about the accuracy of eyewitness testimony. Not only do these results clarify the need for further research on the lay perspective of eyewitness testimony, but they also provide some insight into the way in which many jurors might approach cases involving eyewitness evidence.     

Testifying on Eyewitness Reliability: Expert Advice Is Not Always Persuasive1

This study investigates the impact of different types of expert testimony regarding the unreliability of eyewitness identification. In two hypothetical court cases involving eyewitnesses, expert testimony was presented that was either sample-based (presenting the results of a research program on eyewitness identification) or person-based (presenting information about the particular eyewitness under consideration); the expert either offered causal explanations for his unreliability claim or failed to do so. Two additional control groups (with and without eye-witness identification) were not presented with any expert testimony. The results indicate that subjects who had been confronted with an expert statement made more lenient judgments about the offender but did not discount the eyewitness identification completely. Sample-based information had a moderate impact on the subjects' judgments, regardless of whether or not causal explanations were given. Person-based testimony was the most influential type of expert advice when a causal explanation was provided but the least influential one when no reasons were given. The practical (international differences in admissibility of expert testimony) and theoretical implications (processing of base-rate information) of these findings are discussed.     

Solving the eyewitness problem

Faulty eyewitness testimony is a major source of wrongful convictions. Four solutions are examined to safeguard against mistaken testimony having undue impact: (1) to overturn any conviction based solely on the uncorroborated testimony of a single eyewitness, (2) to require that an attorney be present at any pretrial identification procedure, (3) to allow an expert to testify during the trial about factors of perception and memory that could affect a witness's accuracy, and (4) to have the judge deliver a cautionary instruction to the jury, admonishing them to carefully scrutinize eyewitness testimony, or to educate them about such testimony. Each alternative is discussed within the context of psychological research and legal cases.     

Experimental psychology and the courtroom

Experimental social and cognitive psychology cover a range of topics such as attitudes, attribution, decision making, perception, memory, comprehension, and reasoning. The relevance of these topics to the law is apparent in such domains as jury selection, jury behavior, plea bargaining, eyewitness testimony, sentencing, and police investigation strategies. Despite early attempts to apply experimental psychology to law (circa 1900–1920), it was not until the mid 1970s that a robust law-relevant literature in experimental psychology began to unfold. The experimental psychology/law interface continues to experience some problems in (1) generalizing from specific research experiments to real-world conditions, and (2) identifying solutions rather than just problems.     

Eyewitness testimony: tracing the beliefs of Swedish legal professionals

This paper examines beliefs held by Swedish legal professionals about eyewitness testimony. In a survey including questions about 13 key issues of eyewitness testimony, three groups were investigated: police officers (n = 104), prosecutors (n = 158), and judges (n = 251). The response rate was 74%. Examples of findings are that the beliefs were in line with scientific findings concerning the weapon focus effect, but were not in line for simultaneous vs. sequential lineups. Between-group differences were found for seven items. Judges were much more sceptical than police officers about the reliability and completeness of children's testimonies. The groups seldom agreed about one answer alternative, and they reported not being up to date about scientific research on eyewitness testimony. The results suggest that some important research findings have reached those working on the field. However, they hold many wrongful beliefs about eyewitness testimony, beliefs that might compromise the accuracy of legal decisions.     

Expert testimony and jury decision making: An empirical analysis

This experiment examines the influence of expert psychological testimony on juror decision making in eyewitness identification cases. Experienced jurors and undergraduate mock jurors viewed versions of a videotaped trial, rated the credibility of the eyewitness and the strength of the prosecution's and defense's cases, and rendered verdicts. In the absence of expert testimony jurors were insensitive to eyewitness evidence. Expert testimony improved juror sensitivity to eyewitness evidence without making them more skeptical about the accuracy of the eyewitness identification. Few differences emerged between the experienced jurors and undergraduate mock jurors.     

The Discrediting Effect in Eyewitness Testimony1

Loftus (1974) had subjects read summaries of criminal trials that contained the testimony of either credible or discredited prosecution eyewitnesses, and found no effect of discrediting an eyewitness. Instead, almost as many subjects voted guilty with a discredited eyewitness as with a credible eyewitness; this led Loftus to the conclusion that jurors tend to overbelieve eyewitness testimony. Loftus's conclusion was subsequently challenged by others who reported a strong discrediting effect. A series of three experiments using college students was conducted to explore the characteristics of trial summaries that might account for the discrepancy in results, such as inclusion of judicial instructions concerning proof beyond a reasonable doubt, or an eyewitness's reaffirmation of his testimony following discrediting. In all cases, a strong discrediting effect was found. Apparently the discrediting effect appears regardless of wide variation in content of trial summaries. The present data do not support the overbelief claim.     

Judge's Instruction on Eyewitness Testimony: Evaluation and Revision1

Studies of the reliability of eyewitness identification show that such testimony may frequently be inaccurate; because of this inherent unreliability, the law has established certain safeguards to the use of eyewitness evidence. One safeguard has been the development of an instruction that a judge may use to focus jurors' attention on the eyewitness issue. The effectiveness of this instruction has never been assessed, although other studies confirm that jurors frequently misunderstand or incorrectly use instructions they get from the judge. The purpose of these studies was to evaluate comprehension of this instruction in the context of a videotaped trial and to develop a simplified instruction that would be easier for jurors to understand. Compared to jurors who heard the existing instruction, those with the revised version were more knowledgeable of the factors to consider when listening to eyewitness testimony and were less likely to convict the defendant. A sample of superior court judges in the U.S. thought the simplified instruction was more effective than the existing version at conveying the intended legal concepts to the jury, but also rated it as more strongly biased toward the defense.     

Expert psychological testimony on eyewitness reliability before and after Daubert: the state of the law and the science

This article examines the legal and scientific issues inherent in the use of expert psychological testimony on the factors that affect eyewitness reliability. First, the history of the use of such expert testimony is traced. Next, we look at the criteria that state and federal courts have used in determining whether to admit such testimony, as well as the grounds upon which the testimony has been excluded. We then examine the Daubert decision and discuss its implications for the use of expert eyewitness testimony. We conclude by reviewing eyewitness research and research on jury decision-making that is likely to assume new importance in the post-Daubert era.     

The Psychology of Eyewitness Testimony: A Comparison of Experts and Prospective Jurors

To compare people's beliefs about eyewitness testimony with expert opinion, 79 college students and community adults filled out a questionnaire in which they reported whether they agreed or disagreed with 21 statements previously used in a survey of eyewitness experts (Kassin, Ellsworth, & Smith, 1989). The results indicated that there was a significant inter-item correlation of agreement rates but that subjects differed from the experts on 15 of these items. For courts seeking to determine the extent to which juries need assistance in their evaluations of eyewitness evidence, these findings offer a tentative list of topics worthy of either expert testimony or cautionary instructions from the judge.     

Sensitizing Potential Jurors to Variations in Eyewitness Evidence Quality Using Counterfactual Thinking

Jurors often have difficulty evaluating eyewitness testimony. Counterfactual thinking is a type of mental simulation that informs causal inference. Encouraging jurors to think counterfactually about eyewitness factors may sensitize them to these factors' causal influence on eyewitness identification and testimony accuracy, improving their overall judgments (such as verdicts). One hundred twenty‐one undergraduate participants were randomly assigned to read a scenario containing either high‐quality or low‐quality eyewitness evidence and to evaluate eyewitness factors adopting either their default or a counterfactual mindset via a question‐order manipulation. Logistic regressions and analyses of variance revealed that a counterfactual mindset lowered perceptions of eyewitness accuracy and guilty verdicts (compared with the default mindset) when the evidence was poor; a counterfactual mindset, however, did not increase perceptions of accuracy and guilty verdicts when evidence was strong. We discuss possible mechanisms underlying these effects and identify several potential avenues for future research.Copyright © 2016 John Wiley & Sons, Ltd.     

Can fabricated evidence induce false eyewitness testimony?

False information can influence people's beliefs and memories. But can fabricated evidence induce individuals to accuse another person of doing something they never did? We examined whether exposure to a fabricated video could produce false eyewitness testimony. Subjects completed a gambling task alongside a confederate subject, and later we falsely told subjects that their partner had cheated on the task. Some subjects viewed a digitally manipulated video of their partner cheating; some were told that video evidence of the cheating exists; and others were not told anything about video evidence. Subjects were asked to sign a statement confirming that they witnessed the incident and that their corroboration could be used in disciplinary action against the accused. See‐video subjects were three times more likely to sign the statement than Told‐video and Control subjects. Fabricated evidence may, indeed, produce false eyewitness testimony; we discuss probable cognitive mechanisms. Copyright © 2009 John Wiley & Sons, Ltd.     

Juror Underutilization of Eyewitness Nonidentifications: A Test of the Disconfirmed Expectancy Explanation1

The impact of two types of eyewitness testimony on mock jurors' judgments was explored. A crime eyewitness either testified that the defendant definitely was the robber (identification), definitely was not the robber (nonidentification), or that they weren't sure if he was or was not the robber (control). An alibi eyewitness testified that the defendant either definitely was at the alibi location (identification), definitely was not at the alibi location (nonidentification), or he wasn't sure if the defendant was or was not at the alibi location (control). Strength of case was also manipulated. Results show that crime eyewitness identifications and alibi eyewitness nonidentifications were underutilized. A crime eyewitness by alibi eyewitness interaction revealed that within the crime eyewitness identification condition alibi identification was underutilized whereas with the other two crime eyewitness conditions, alibi nonidentification information was underutilized. The results supported a disconfirmed expectancy explanation.     

Rape myth acceptance: A case for providing educational expert testimony in rape jury trials

The prevalence and content of rape myth acceptance indicate a need for educational expert testimony in rape jury trials. It is proposed that expert testimony regarding common misconceptions about rape and rape victim behavior, conceptualized in terms of a social framework, would help to compensate for societal bias against the complainant in a rape trial. Rape trauma syndrome, eyewitness identification, and general educational testimony concerning rape are discussed. Evidence is presented that suggests inclusion of such testimony serves the purpose of expert testimony according to the Federal Rules of Evidence.     

Why Do Eyewitnesses Make So Many Mistakes?

Previous research on eyewitness identification has demonstrated high rates of error. Subjects have frequently identified innocent targets as the "criminal" they had seen earlier (false identifications) or had falsely claimed that the criminal was not in the line-up (misses). The present study examines whether identification error rates are inflated by pressures in the typical experimental situation to "make a guess" regardless of one's confidence in the accuracy of the response. It was found that providing an explicit option for subjects to respond "don't know" significantly decreased false identifications and misses with no cost to the proportion of correct identifications. The addition of written and verbal instructions emphasizing the acceptability of the "don't know" option produced a marginally significant further decline in identification errors, again without cost to correct identifications. The discussion considered implications of the present results for experimental and actual police line-up procedures.     

Nonadversarial Methods for Sensitizing Jurors to Eyewitness Evidence

Tested the effects, on juror decision making, of court-appointed expert testimony and judge's instructions designed to sensitize jurors to eyewitness evidence. Subjects ( N = 144) viewed a videotaped trial in which the primary evidence was the testimony of and identification by an eyewitness. Three levels of expert advice (court-appointed expert, judge's instructions, no expert advice) were crossed with two levels of witnessing and identification conditions and two levels of witness confidence The court-appointed expert produced skepticism toward the identification but did not improve juror sensitivity to the eyewitness evidence. The judge's instructions produced neither skepticism or sensitization effects.     

Degree of Detail of Eyewitness Testimony and Mock Juror Judgments1

The influence of the degree of detail of eyewitness testimony on two sides of a court case was investigated in two experiments. In the first experiment subject-jurors read a civil court case involving an automobile-pedestrian accident. The plaintiff and the defendant presented conflicting eyewitness accounts. Judgments of the relative credibility of the eyewitnesses on each side and the percentage of negligence of the parties were influenced by the relative degree of detail of the eyewitness testimony on each side. In the second experiment subject-jurors read a criminal court case involving robbery and murder. The prosecution and defense presented conflicting eyewitness accounts. The degree of detail of the prosecution eyewitness testimony influenced judgments of guilt and judgments of the credibility of the eyewitnesses. An examination of the reasons for verdicts and credibility judgments revealed that some subjects inferred that an eyewitness who gave testimony with a greater degree of detail had a better memory for the trivial details and the culprit than an eyewitness who gave testimony with a lesser degree of detail. Implications of these results for the legal system are discussed.     

The effect of cross‐examination on the accuracy of adult eyewitness testimony

Cross‐examination permits styles of questioning that increase eyewitness error (e.g. leading questions). Previous research has shown that under cross‐examination children change many of their initially accurate answers. An experiment is reported in which the effect of cross‐examination on accuracy of adult eyewitness testimony was investigated. Twenty‐two student witnesses watched a video of a staged theft, either in pairs, or individually. Paired witnesses discussed the video with their co‐witnesses, but did not know they had seen slightly different versions. Participants in the co‐witness condition demonstrated memory conformity and recalled less accurately than witnesses in the control condition. After approximately 4 weeks all participants were cross‐examined by a trainee barrister. Following cross‐examination there was no difference in accuracy between the two experimental groups. Witnesses in both conditions made many changes to their previous reports by altering both initially correct and incorrect answers. The results demonstrate negative effects of cross‐examination on the accuracy of adult eyewitness testimony. Copyright © 2010 John Wiley & Sons, Ltd.