Steven D. Penrod

Eyewitness Identification Procedures: Recommendations for Lineups and Photospreads

There is increasing evidence that false eyewitness identification is the primary cause of the conviction of innocent people. In 1996, the American Psychology/Law Society and Division 41 of the American Psychological Association appointed a subcommittee to review scientific evidence and make recommendations regarding the best procedures for constructing and conducting lineups and photospreads. Three important themes from the scientific literature relevant to lineup methods were identified and reviewed, namely relative-judgment processes, the lineups-as-experiments analogy, and confidence malleability. Recommendations are made that double-blind lineup testing should be used, that eyewitnesses should be forewarned that the culprit might not be present, that distractors should be selected based on the eyewitnesss verbal description of the perpetrator, and that confidence should be assessed and recorded at the time of identification. The potential costs and benefits of these recommendations are discussed.

Eyewitness Evidence: Improving Its Probative Value

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 eyewitnesss 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 Münsterbergs 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.

Juror sensitivity to eyewitness identification evidence.

A mock-jury study was conducted to examine juror sensitivity to eyewitness identification evidence. Subjects were 129 eligible and experienced jurors from Dane County, Wisconsin, who viewed a videotaped trial that involved an eyewitness identification. Ten factors associated with the crime and the identification (e.g., disguise of the perpetrator, retention interval, confidence of the witness) were manipulated. The results of this mock-jury study were combined with those of a previous study using the same experimental stimuli and procedures, but using undergraduates as subjects. This analysis showed that the confidence of the eyewitness was the most powerful predictor of verdicts (p<.05) and that differences between undergraduates and eligible jurors in their sensitivity to eyewitness evidence were negligible.

Witness confidence and witness accuracy: Assessing their forensic relation.

Jurors overbelieve eyewitnesses, have difficulty reliably differentiating accurate from inaccurate eyewitnesses, and are not adequately sensitive to aspects of witnessing and identification conditions. A major source of juror unreliability is reliance on witness confidence, a dubious indicator of ey

Methodological variables in Web-based research that may affect results: Sample type, monetary incentives, and personal information

There are many methodological differences between Web-based studies, differences that could substantially affect the results. The present study investigated whether sample type, offering payment through a lottery, and requiring participants to enter personal information would affect dropout rates and/or the substantive results in a study of jury decision making in capital cases. Asking participants to enter their e-mail addresses increased dropout rates, and offering payment through a lottery tended to do so as well. Participants offered payment tended to be less likely to give death sentences, and sample type moderated the influence of attitudes toward the death penalty on verdicts.

Web-based research: Methodological variables’ effects on dropout and sample characteristics

Previous research has made a beginning in addressing the importance of methodological differences in Web-based research. The present paper presents four studies investigating whether sample type, financial incentives, time when personal information is requested, table design, and method of obtaining informed consent influence dropout and sample characteristics(both demographics and measured attitudes). Undergraduates were less likely to drop out than nonstudents, and nonstudents offered a financial incentive were less likely to drop out than those offered no incentive. Complex tables, tables that were too wide, requests for personal information on the first page, and the imposing of additional informed consent procedures each provoked early dropout. As was expected, nonstudents and those presented with complex tables showed more measurement error and attitude differences. Asking for personal information and imposing additional consent procedures affected the demographic makeup, raising challenges to external validity.

EXPLORING THE EFFECTS OF ATTITUDES TOWARD THE DEATH PENALTY ON CAPITAL SENTENCING VERDICTS

Attitudes toward the death penalty are multifaceted and strongly held, but little research outside of the death-qualification literature has focused on the role that such attitudes and beliefs play in jurors’ capital sentencing verdicts. A single item is insufficient to properly measure attitudes toward the death penalty; therefore, a new 15-item, 5-factor scale was constructed and validated. Use of this scale in 11 studies of capital jury decision making found a large effect of general support of the death penalty on sentencing verdicts as well as independent aggravating effects for the belief that the death penalty is a deterrent and the belief that a sentence of life without parole nonetheless allows parole. These effects generally were not completely mediated by, nor did attitudes moderate the effects of, aggravating and mitigating factors. Through death qualification and voir dire, the legal system attempts to strike a balance between jurors’ attitudes toward the death penalty and a defendant’s right to an impartial jury. Courts embrace the fact that capital jurors’ attitudes toward the death penalty influence their decisions whether to sentence a defendant to death: “A jury that must choose between life imprisonment and capital punishment can do little more—and must do nothing less—than express the conscience of the community on the ultimate question of life or death” (Witherspoon v. Illinois, 1968, p. 519). However, the defendant’s right to an impartial jury requires that jurors also be able to follow the law and not reach a verdict based solely on their attitudes. Courts currently balance these interests by allowing parties to exclude for cause only those jurors whose attitude toward the death penalty is so strong, either for or against, that it would “prevent or substantially impair the performance of [their] duties as a juror” (Wainwright v. Witt, 1985, p. 424). To ascertain whether jurors fail this test, defendants are entitled to an adequate voir dire that consists of more than general questions and that is sufficient to allow the defendant to uncover biases to which jurors do not readily admit (Morgan v. Illinois, 1992). Afterward, death-qualified capital jurors must (though the specifics vary by

Performance feedback improves the resolution of confidence judgments

Abstract A training experiment was carried out to examine whether feedback concerning the appropriateness of confidence judgments, given in terms of probability, improves calibration and resolution skills. Subjects participated in four separate sessions in which they responded to a series of general knowledge questions. Immediately before completing the questionnaires in Sessions 2, 3, and 4, half of the subjects were given detailed feedback concerning their confidence levels and accuracy rates. The remaining half were given no such feedback, and thus served as a control group. The resolution of confidence judgments improved across sessions to a greater extent for the group exposed to performance feedback than for the control group. Calibration of confidence judgments was uninfluenced by the performance feedback manipulation.

THE EFFECTS OF DAUBERT ON THE ADMISSIBILITY OF EXPERT TESTIMONY IN STATE AND FEDERAL CRIMINAL CASES

Appellate opinions were evaluated on variables related to expert admissibility to assess the effects of Daubert v. Merrell Dow Pharmaceuticals, Inc. in criminal cases. Analysis reveals changes in appellate courts’ consideration of Frye v. United States, the 4 Daubert criteria, and several Federal Rules of Evidence. The importance of Frye and the general acceptance criterion decreased over time, and the importance of the Daubert criteria increased over time. However, these changes were not consistent for all types of testimony. Overall, there is greater reliance on Daubert when determining the admissibility of a scientific expert. However, only criteria related to the Federal Rules of Evidence are reliably related to admissibility decisions. Details of appellate court application of the 4 Daubert criteria, the Federal Rules of Evidence, and other related factors are discussed.

Jury decision-making biases and methods to counter them

Purpose. The objective of this review was to give a broad overview of various biases associated with jury decision making. Specifically we review research on the impact of pretrial publicity, jury instructions, inadmissible evidence, and scientific evidence. This article elucidates various challenges jurors may face across systems around the world and remedies to counter these challenges. Results. After 50 years of scientific research on juries and juror decision making, there are still many gaps in understanding how factors such as pretrial publicity, inadmissible evidence, scientific evidence, and jury instructions influence juries. At the same time the field has developed a level of appreciation for these problems and is making strives toward understanding them. Conclusion. Based on this review some conclusions can be drawn regarding the areas of decision making reviewed. Jury instructions: Research shows that jurors have difficulties in understanding pattern instructions, at the same time we have developed some insights into ways instructions can be rewritten to increase comprehensibility. Inadmissible evidence: We are aware of the cognitive effort involved in attempting to disregard evidence but are at this point unclear on how to eliminate the associated problems. Scientific evidence: Research has illuminated the difficulties jurors have with comprehending scientific evidence. Better education of jurors and judges can help to address this issue. Pretrial publicity: The threats posed by pretrial publicity to the defendants right to a fair trial are clear. At the same time (save change of venue) there is a need to develop cost-effective remedies to help overcome media-induced biases.