The Influence of Eyewitness Nonidentifications on Mock-Jurors' Judgments of a Court Case1

Two experiments examined the effect of an eyewitness nonidentificution on mock-jurors' verdicts in robbery cases, as well as the effects of number of identifying eyewitnesses and status of the identifying witness (victim or bystander). Subjects read court case summaries that included variable eyewitness evidence and constant alibi, circumstantial, and character evidence. In Experiment 1, frequency of guilty verdicts was significantly less when an eyewitness testified in court that the defendant was not the perpetrator, even when this nonidentification opposed two positive identifications. In Experiment 2, a low guilty rate was again associated with the presence of a nonidentifier, but only when the nonidentifier actually testified in court and stipulated that the defendant is “not the man.” On the average, 70% of the jurors delivered guilty verdicts when both the victim and bystander gave identifying testimony, whereas 12.5% delivered guilty verdicts when the bystander gave opposing nonidentifying testimony. Guilty rates were unaffected by the identifying eyewitness' status and (in Experiment 2, but not Experiment 1) were higher when there were two (vs. one) identifying eyewitnesses.     

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 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.     

An Analysis of the Self-Handicapping Scale

Two experiments explored the impact of a highly publicized news event (the mistaken identification of an innocent man) on juror decision-making. In Experiment 1,168 students rendered verdicts after reading about a trial that involved eyewitness testimony. Subjects who participated in the experiment while the critical story was prominently in the news were less likely to convict a hypothetical defendant than subjects who participated three months before or afterward. In Experiment 2, subjects were 72 ordinary citizens who either had or had not read a magazine article about a mistakenly identified man. The former subjects were less likely to convict than the latter. These results raise questions about the extent to which current local or world events influence the outcome of psychological research and courtroom trials.     

Memory and judgment: Availability versus explanation-based accounts

Two theories about the relationship between memory and decisions are examined. In an explanation-based model, the organization in memory of decision-relevant information determines decisions. In an availability model, the amount of information sampled from memory that supports competing decisions is crucial. In Experiment 1, subjects read evidence from a legal trial, made decisions, and provided free-recall data. Evidence presentation order was manipulated to produce differences in evidence coherence. When the prosecution evidence order was coherent, the subjects were more likely to choose guilty verdicts, and recall of prosecution evidence, relative to defense evidence, was greater. Thus, both evidence coherence and availability of information in memory could account for the basic findings. In Experiment 2, recall differences were eliminated as a function of evidence order. The results show that verdict effects favoring the more coherent prosecution evidence are obtained even when the relative amounts of prosecution and defense recall are equated across conditions.     

The Timing of the Defense Opening Statement: Don't Wait Until the Evidence Is in1

Defense attorneys often reserve their opening statements until after presentation of evidence by the prosecution, a practice advocated by some experts. The current study, involving 291 subjects, varied the timing of the defense attorney's opening statement so that it preceded the prosecutor's opening statement, immediately followed the prosecutor's opening statement, or was reserved until after the prosecutor's case presentation. The type of opening statement (content vs. noncontent) and the testimony (altered vs. unaltered) were varied for purposes of increasing generalization. Materials were based on an actual case of auto theft and were presented in written form complete with judge's instructions. The results showed that subjects perceived eyewitness testimony, the prosecutor's opening statement, the prosecutor's closing statement, the defense attorney's closing statement, and the effectiveness of the attorneys differently depending on the timing of the opening statement. Each of these items favored the defense more than the prosecution if the defense opening statement was earlier rather than later. These effects did not interact with type of opening statement or the testimony alteration variable. Individual verdicts, when weighted by the subjects' confidence in their verdicts, were also affected by the timing variable with verdicts more favorable to the defense when the defense opening statement was given earlier rather than later. The consistency with which the timing variable affected subjects' impressions suggests that defense attorneys who take their first opportunity to make an opening statement, rather than delay, end up with a stronger case for their client. Possible exceptions to this conclusion 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.     

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.     

An Aiibi Witness' Influence on Mock Jurors' Verdicts1

The impact of alibi testimony on juror decision making is not yet clear because it has been examined empirically infrequently. This study was designed to determine the impact of alibi witness' testimony, the impact of an alibi witness with a relationship in comparison to one without a relationship to the defendant, and the impact of an eyewitness' confidence on juror decision making. Results indicated that mock jurors acquit a defendant more often when an alibi witness with no relationship to the defendant testified on his behalf. Participants did not believe an alibi witness who had a relationship with the defendant even though the witness was not a family member. Implications for these results are discussed.     

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.     

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.     

An archival study of eyewitness memory of the Titanic's final plunge

A handful of real-life studies demonstrate that most eyewitnesses accurately recall central details (i.e., the gist of what happened) from traumatic events. The authors evaluated the accuracy of archival eyewitness testimony from survivors of the Titanic disaster who witnessed the ship's final plunge. The results indicate that most eyewitness testimony (15 eyewitnesses of 20) is consistent with forensic evidence that demonstrates that the Titanic was breaking apart while it was still on the ocean's surface. Despite the methodological limitations of archival research, the authors provide evidence from a single-occurrence traumatic event (with a large-scale loss of life) that the majority of eyewitnesses accurately recall central details.     

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.     

Evaluating Identification Evidence from Multiple Eyewitnesses

When two or more eyewitnesses provide identification evidence in a given investigation, their testimony will be characterized either by unanimity or by contradictions. In the present research, nominal groups of several sizes were constructed from the distributions of individual responses in a variety of previous studies. It was found that both unanimity and contradictions could be expected to occur with considerable frequency. When unanimity occurred, the unanimous response was very likely to be accurate, particularly in large groups. When contradictions occurred, the most common, or modal, response was most probably accurate, particularly when four or more witnesses endorsed the modal position. These and several subsidiary findings resulted largely from the fact that individual errors were randomly distributed across many different incorrect response options. Consequently, even when eyewitnesses were generally inaccurate, the correct option was still chosen more frequently than any single incorrect option. Distinctions between the implications of individual vs. multiple eyewitness testimony were discussed.     

An Archival Study of Eyewitness Memory of the Titanic's Final Plunge

A handful of real-life studies demonstrate that most eyewitnesses accurately recall central details (i.e., the gist of what happened) from traumatic events. The authors evaluated the accuracy of archival eyewitness testimony from survivors of the Titanic disaster who witnessed the ship's final plunge. The results indicate that most eyewitness testimony (15 eyewitnesses of 20) is consistent with forensic evidence that demonstrates that the Titanic was breaking apart while it was still on the ocean's surface. Despite the methodological limitations of archival research, the authors provide evidence from a single-occurrence traumatic event (with a large-scale loss of life) that the majority of eyewitnesses accurately recall central details.     

Trivial persuasion in the courtroom: the power of (a few) minor details

Investigated the influence of trivial testimonial detail on judgments of 424 undergraduates who served as mock jurors. Ss read a summary of a court case involving robbery and murder. In Experiment 1, detailed testimony influenced judgments of guilt, even when the detail was unrelated to the culprit. In Experiment 2, detailed testimony was especially powerful when an opposing witness testified that she could not remember the trivial details. Subsequent analyses suggest that the impact of detailed testimony on guilt judgments is mediated by inferences about the eyewitnesses. When eyewitnesses provided more detail, they were generally judged to be more credible, to have a better memory for the culprit's face and for details, and to have paid more attention to the culprit.     

Race,Rape, and Bias: Distortion of Prior Odds and Meaning Changes

Two experiments were conducted to investigate how racial bias affects juror decision making. Three sources of bias were studied: (1) prior probabilities of guilt, (2) distortion of the meaning of evidence, and (3) differential weighting of information. A paired comparison technique employed in the first study revealed that pretrial probabilities of guilt were greater when the victim was White than when she was Black. In the second experiment, a different group of subjects viewed one of four videotaped simulated rape trials in which seven segments of testimony had been previously rated as pro-prosecution, pro-defense, or neutral. During the trial, subjects rated each segment on three different scales: prosecution, defense, and degree of defendant guilt. Results indicated that neutral evidence was seen as more favorable to prosecution for a White victim compared to a Black victim. Evidence which favored either prosecution or defense was not distorted. Regression analyses revealed a positive relationship between estimates of guilt and distortion of evidence. The weight or importance of the evidence did not vary as a function of victim or defendant race. Years of recommended imprisonment indicated greater severity toward the Black assailant of a White woman. The results suggest that bias in favor of White victims occurs both in the assessment of pretrial probabilities and perception of evidence.