Eyewitness identification evidence and innocence risk

It is well known that the frailties of human memory and vulnerability to suggestion lead to eyewitness identification errors. However, variations in different aspects of the eyewitnessing conditions produce different kinds of errors that are related to wrongful convictions in very different ways. We present a review of the eyewitness identification literature, organized around underlying cognitive mechanisms, memory, similarity, and decision processes, assessing the effects on both correct and mistaken identification. In addition, we calculate a conditional probability we call innocence risk, which is the probability that the suspect is innocent, given that the suspect was identified. Assessment of innocence risk is critical to the theoretical development of eyewitness identification research, as well as to legal decision making and policy evaluation. Our review shows a complex relationship between misidentification and innocence risk, sheds light on some areas of controversy, and suggests that some issues thought to be resolved are in need of additional research.     

Cognitive science and the law

Numerous innocent people have been sent to jail based directly or indirectly on normal, but flawed, human perception, memory and decision making. Current cognitive-science research addresses the issues that are directly relevant to the connection between normal cognitive functioning and such judicial errors, and suggests means by which the false-conviction rate could be reduced. Here, we illustrate how this can be achieved by reviewing recent work in two related areas: eyewitness testimony and fingerprint analysis. We articulate problems in these areas with reference to specific legal cases and demonstrate how recent findings can be used to address them. We also discuss how researchers can translate their conclusions into language and ideas that can influence and improve the legal system.     

An editorial overview

Now is an excellent time to be doing research at the intersection of psychology and law. In the last few years, both the legal system and the legal academic community have taken more and more interest in the empirical findings of cognitive and social psychologists. Much of this interest has been provoked by the large number of convicted people who have been exonerated by DNA evidence. Examination of their cases reveals that most are associated with one (or more) of the following problems: bad eyewitness testimony, a false confession, or flawed forensic evidence. These issues are ones that psychologists have been investigating for years. For those of you new to this area, we recommend Elizabeth Loftus’s foundational work on so many areas of memory, Gary Wells’s work on eyewitness identification, Saul Kassin’s work on false confessions, and Reid Hastie’s work on jury decision making. All have written for both psychological and legal audiences.     

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.     

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 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.     

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.     

Revisiting absolute and relative judgments in the WITNESS model

The WITNESS model (Clark in Applied Cognitive Psychology 17:629–654, 2003) provides a theoretical framework with which to investigate the factors that contribute to eyewitness identification decisions. One key factor involves the contributions of absolute versus relative judgments. An absolute contribution is determined by the degree of match between an individual lineup member and memory for the perpetrator; a relative contribution involves the degree to which the best-matching lineup member is a better match to memory than the remaining lineup members. In WITNESS, the proportional contributions of relative versus absolute judgments are governed by the values of the decision weight parameters. We conducted an exploration of the WITNESS model’s parameter space to determine the identifiability of these relative/absolute decision weight parameters, and compared the results to a restricted version of the model that does not vary the decision weight parameters. This exploration revealed that the decision weights in WITNESS are difficult to identify: Data often can be fit equally well by setting the decision weights to nearly any value and compensating with a criterion adjustment. Clark, Erickson, and Breneman (Law and Human Behavior 35:364–380, 2011) claimed to demonstrate a theoretical basis for the superiority of lineup decisions that are based on absolute contributions, but the relationship between the decision weights and the criterion weakens this claim. These findings necessitate reconsidering the role of the relative/absolute judgment distinction in eyewitness decision making.     

目击证人研究

目击证人的证词对维持司法系统公正的重要性使得对目击证人的研究成为当今法律心理学和司法领域的热点之一。目击证人的错误证词是导致锗判案件的最常见原因。警方在询问、队列辨认与照片识别中的特定程序和行为,目击证人的记忆、年龄、性别、种族、自信程度等．都将影响证词的准确性。     

How psychiatrists and judges assess the dangerousness of persons with mental illness: an 'expertise bias"

When assessing dangerousness of mentally ill persons with the objective of making a decision on civil commitment, medical and legal experts use information typically belonging to their professional frame of reference. This is investigated in two studies of the commitment decision. It is hypothesized that an 'expertise bias' may explain differences between the medical and the legal expert in defining the dangerousness concept (study 1), and in assessing the seriousness of the danger (study 2). Judges define dangerousness more often as harming others, whereas psychiatrists more often include harm to self in the definition. In assessing the seriousness of the danger, experts tend to be more tolerant with regard to false negatives, as the type of behavior is more familiar to them. The theoretical and practical implications of the results are discussed.     

ROCs in Eyewitness Identification: Instructions versus Confidence Ratings

From the perspective of signal detection theory, different lineup instructions may induce different levels of response bias. If so, then collecting correct and false identification rates across different instructional conditions will trace out the receiver operating characteristic (ROC)—the same ROC that, theoretically, could also be traced out from a single instruction condition in which each eyewitness decision is accompanied by a confidence rating. We tested whether the two approaches do in fact yield the same ROC. Participants were assigned to a confidence rating condition or to an instructional biasing condition (liberal, neutral, unbiased, or conservative). After watching a video of a mock crime, participants were presented with instructions followed by a six‐person simultaneous photo lineup. The ROCs from both methods were similar, but they were not exactly the same. These findings have potentially important policy implications for how the legal system should go about controlling eyewitness response bias.Copyright © 2017 John Wiley & Sons, Ltd.     

Lay knowledge of eyewitness behaviour: A British survey

One of the recent concerns in the study of eyewitness memory is how well lay knowledge, i.e. ‘common sense’, matches the findings of empirical research. A number of American and Canadian studies, some using questionnaire methodology, have found limitations in lay knowledge of eyewitness behaviour. Further studies have extended this general finding beyond the lay public–who are prospective jurors–to legal professionals such as lawyers and policemen. The present study utilized the Knowledge of Eyewitness Behaviour Questionnaire (KEBQ), an inventory used in previous studies, to replicate the North American studies with a British sample of students, including law students, and the general public. The results showed a great similarity between the North American and British samples' knowledge of eyewitness behaviour. A significant number of correct responses were made to eight of the 14 KEBQ items, with a significant number of incorrect responses to the remainder. It was also found that law students were no more knowledgeable than other subjects; that knowledge did not vary with age; and that previous experience as an eyewitness was not related to knowledge of eyewitness behaviour. In responding to some of the criticisms of questionnaire studies it is argued that the evidence is mounting in favour of the need for a recognized system to make jurors aware of the factors known to influence eyewitness testimony.     

Two Pairs of Conflicting Motives in Decision Making

A concept is proposed that decision making consists of resolving two conflicts. One of them is between the desire to make an accurate decision and the desire to minimize the effort of making a choice. The second conflict is between the desire to make an accurate decision and the desire that this decision is distinct. To operationalize basic motives involved in decision making, as assumed in the model, a new process tracing technique has been developed. Using this technique, three experiments were performed to test the predictions of the model. The experiments supported the predictions concerning the conflict between accuracy and distinctness. Similarity of choice alternative and decision importance appeared to affect the way the conflict between accuracy and distinctiveness is solved. An alternative explanation of the results obtained and perspectives of further research are discussed.     

Perspectives on Psychology and Law

The past decade saw an explosive growth in psychological research on law (particularly the judicial process) that continues unabated. This article presents an intellectual history of this research and a critical assessment of its contemporary developments. It begins by tracing four stages in the relations between psychology and law that serve to place present scholarship in perspective. Then follow two sections consisting of conceptual, methodological, and jurisprudential critiques of two topics, respectively, that traditionally have been and still remain at the center of research attention: the pretrial phase of the criminal process (eyewitness identifications) and the criminal trial itself (jury selection, jury decision making, and presentations of evidence and law to the jury). Finally, some themes are culled from past and present experience that capture the mood, difficulties, and prospects of applying psychology to the law. The purpose of this theoretical overview of the field is to suggest some insights into two recurrent questions: why has psychological research not had more of an impact on the judicial process, and what can be done about it?     

What US judges know and believe about eyewitness testimony

In a survey, 160 US judges indicated their knowledge and beliefs about eyewitness testimony. Although correct on some issues, judges were often wrong on important issues such as whether at trial eyewitness confidence is a good indicator of eyewitness accuracy, and if jurors can distinguish accurate from inaccurate witnesses. Increased knowledge was associated with: a willingness to permit legal safeguards, including expert testimony at trial; a belief that jurors have limited knowledge of eyewitness factors; a reluctance to convict defendants solely from eyewitness testimony; a more accurate estimate of the extent to which wrongful convictions result from eyewitness error; and a belief that judges need more eyewitness training. Additional training about factors and procedures that affect eyewitness accuracy may help judges reduce the number of wrongful convictions. Copyright © 2004 John Wiley & Sons, Ltd.     

Truth and Consequences: The Effect of Responsibility on Eyewitness Behavior

Previous research has revealed that eyewitness identification errors are so common as to render such testimony of questionable value as courtroom evidence. However, all of this research was conducted in settings where the eyewitnesses were not responsible for the consequences of their responses—that is, they were aware they were in an experiment. The present research compared eyewitness behavior in an explicitly experimental setting with behavior in a setting that the subjects perceived to be real and in which loss of time, potential embarrassment and discomfort, a student's reputation, and the validity of a scholarship competition were at stake. Surprisingly, two studies both found that subjects were just as willing to offer information, just as willing to make a positive identification, and just as inaccurate in the real as in the experimental setting. These results indicate that previous research has accurately portrayed eyewitness error rates in actual investigations. Implications of the present research for the use of eyewitness testimony are discussed.