Effects of Experiencing the Eyewitness Identification Procedure on Juror Decisions

Mistaken eyewitness identifications are believed to contribute to a preponderance of wrongful convictions, underscoring the need to identify methods to help decrease the likelihood of false convictions based on eyewitness testimony. The present study tested the hypothesis that providing jurors with first-hand experience with eyewitness identification procedures could help further sensitize them to the limitations of eyewitness testimony. Eighty college students watched a videotaped mock trial in which the prosecution’s sole evidence was eyewitness testimony. In a 2 × 2 randomized factorial design, we manipulated whether participants heard expert psychological testimony (henceforth referred to as expert testimony) on the limitations of eyewitness identification and whether they experienced an eyewitness identification procedure. As predicted, experiencing the eyewitness identification procedure had a significant impact on juror decisions, suggesting that this procedure could further help reduce the likelihood of wrongful convictions.     

On the Power of Confession Evidence: An Experimental Test of the Fundamental Difference Hypothesis

In Arizona v. Fulminante (1991), a U.S. Supreme Court majority stated that confessions are similar to, not fundamentally different from, other types of evidence. To evaluate this claim, three mock juror studies compared the impact of confessions to other common forms of evidence. In Experiment 1, participants read summaries of four criminal trials (murder, rape, assault, theft), each of which contained a confession, an eyewitness identification, character testimony, or none of the above. Significantly, the confessions produced the highest conviction rates. In Experiments 2 and 3, participants read a murder or assault trial containing all three types of evidence and made a series of midtrial judgments. Results indicated that the confession was seen as the most incriminating, followed by the eyewitness and character testimony. Although the comparisons we made are limited in certain respects, our findings suggest that confessions are uniquely potent.     

Secondary Confessions as Post-identification Feedback: How Jailhouse Informant Testimony Can Alter Eyewitnesses’ Identification Decisions

Prior research has shown that primary confession evidence can alter eyewitnesses’ identifications and self-reported confidence. The present study investigated whether secondary confession evidence from a jailhouse informant could have the same effect. Participants (N?=?368) watched a video of an armed robbery and made an identification decision from a photo lineup. Except for those in the no-feedback conditions, all participants then read that certain lineup members either confessed to the crime, denied involvement, or were implicated by a jailhouse informant. Jailhouse informant testimony implicating the identified lineup member led participants to have significantly higher confidence in their identification. In contrast, jailhouse informant testimony that implicated a lineup member other than the identified led participants to have significantly lower confidence in their initial identification, and 80% of these witnesses changed their identification. These results indicate that jailhouse informant testimony can influence eyewitnesses’ confidence and their identification decisions.     

Dueling experts and imperfect verification

In the Dueling Experts Game, adversarial experts strategically produce “good” or “bad” evidence to support their partisan testimony. Good evidence is probative while bad evidence has no evidentiary value. The new feature of this Game is that Judge sometimes erroneously identifies good evidence as bad evidence and vice versa. Along the Game’s equilibrium path, each partisan expert produces only good evidence if it supports his side. When favorable good evidence is unavailable, an expert produces bad evidence to support his testimony. Hence, dueling experts always contradict one another. Despite their conflicting testimony, one of the experts invariably produces the available good evidence for Judge. Therefore, Judge always receives the available good evidence. A central result is that the quality of experts, including their ability to persuade judges using available good evidence, and the quality of judges – their ability to distinguish good from bad evidence – determine the accuracy of verdicts. Remarkably, the likelihood that experts are endowed with good evidence does not matter provided that this likelihood is not identically zero or one.     

Elasticity in evaluations of criminal evidence: Exploring the role of cognitive dissonance

Purpose. Previous experiments have demonstrated asymmetrical scepticism in investigators' judgments of criminal evidence – evidence inconsistent (vs. consistent) with the dominant hypothesis about a case is judged as less reliable. In addition, some types of evidence (e.g., witness testimony) are more susceptible to asymmetrical scepticism than others (e.g., DNA evidence), indicating varying degrees of elasticity. This article proposes that inconsistent evidence arouses cognitive dissonance, and that the dissonance can be reduced through either asymmetrical scepticism (for high‐elasticity evidence) or belief change (for low‐elasticity evidence). The hypotheses are tested in two experiments. Methods. In both experiments, law students made a preliminary judgment about the guilt of a suspect in a homicide case, and subsequently received a piece of DNA or witness evidence which was either consistent or inconsistent with the preliminary judgment. The extent to which participants changed their guilt judgments, judged the additional evidence as reliable, and felt dissonance served as the main dependent variables. Results. Inconsistent (vs. consistent) evidence did arouse stronger dissonance, but only for witness (and not DNA) evidence. Experienced dissonance (Experiment 1) and dissonance reduction (Experiment 2) accounted for the effect of the evidence on changes in guilt judgments, but not for the effect on reliability judgments. The greatest dissonance reduction was observed among participants who received inconsistent witness evidence but did not change their guilt judgments accordingly. Conclusions. It appears that dissonance plays a significant, although complex, role in investigative judgments of guilt and reliability. Alternative dissonance‐reducing mechanisms that can account for the findings and practical implications are discussed.     

Forensic Confirmation Bias: Do Jurors Discount Examiners Who Were Exposed to Task-Irrelevant Information?*†

Knowledge of task-irrelevant information influences judgments of forensic science evidence and thereby undermines their probative value (i.e., forensic confirmation bias). The current studies tested whether laypeople discount the opinion of a forensic examiner who had a priori knowledge of biasing information (i.e., a defendant's confession) that could have influenced his opinion. In three experiments, laypeople (N = 765) read and evaluated a trial summary which, for some, included testimony from a forensic examiner who was either unaware or aware of the defendant's confession, and either denied or admitted that it could have impacted his opinion. When the examiner admitted that the confession could have influenced his opinion, laypeople generally discounted his testimony, as evidenced by their verdicts and other ratings. However, when the examiner denied being vulnerable to bias, laypeople tended to believe him—and they weighted his testimony as strongly as that of the confession-unaware examiner. In short, laypeople generally failed to recognize the superiority of forensic science judgments made by context-blind examiners, and they instead trusted examiners who claimed to be impervious to bias. As such, our findings highlight the value of implementing context management procedures in forensic laboratories so as not to mislead fact-finders.     

The Effects of General Pretrial Publicity on Juror Decisions: An Examination of Moderators and Mediating Mechanisms

Two studies examined three moderators (gender, attitudes, and media slant) and four mediators (accessibility, evidence importance, evidence plausibility, and standards of guilt) of general pretrial publicity's influence on juror decisions. In Study 1, participants who watched a prodefense rape story were more likely to report that they would need more inculpatory evidence to convict a defendant of rape than were participants who watched a proprosecution rape story. In Study 2, participants watched news stories, one of which was a proprosecution rape story, a prodefense rape story, or a nonrape story. In an ostensibly unrelated study, participants indicated their attitudes toward rape, watched a rape trial, and provided trial and witness ratings. Accessibility did not mediate the media effects on participants' judgments of rape importance; however, attitudes moderated media effects. Rape news influenced juror ratings of the importance of evidence about the complainant's behavior. Finally, media altered the standards participants used to determine defendant guilt. Implications for understanding the mechanisms responsible for pretrial publicity effects are discussed.     

Error Rates,Likelihood Ratios,and Jury Evaluation of Forensic Evidence

Forensic examiners regularly testify in criminal cases, informing the jurors whether crime scene evidence likely came from a source. In this study, we examine the impact of providing jurors with testimony further qualified by error rates and likelihood ratios, for expert testimony concerning two forensic disciplines: commonly used fingerprint comparison evidence and a novel technique involving voice comparison. Our method involved surveying mock jurors in Amazon Mechanical Turk (N = 897 laypeople) using written testimony and judicial instructions. Participants were more skeptical of voice analysis and generated fewer “guilty” decisions than for fingerprint analysis (B = 2.00, OR = 7.06, p = <0.000). We found that error rate information most strongly decreased “guilty” votes relative to no qualifying information for participants who heard fingerprint evidence (but not those that heard voice analysis evidence; B = −1.16, OR = 0.32, p = 0.007). We also found that error rates and conclusion types led to a greater decrease on “guilty” votes for fingerprint evidence than voice evidence (B = 1.44, OR = 4.23, p = 0.021). We conclude that these results suggest jurors adjust the weight placed on forensic evidence depending on their prior views about its reliability. Future research should develop testimony and judicial instructions that can better inform jurors of the strengths and limitations of forensic evidence.     

Expert testimony in child sexual abuse cases

We presented participants with syndromal, witness credibility, or anatomically detailed doll evidence to determine (a) whether these different types of expert evidence exert differential influence on participants' judgments and (b) whether the influence of this evidence could be better explained by the relative scientific status or the probabilistic qualities of the research presented. Additionally, we investigated whether a strong or weak cross-examination of the expert would be more successful in discrediting the information provided in the expert's testimony. Findings suggest that participants are less influenced by expert testimony based on probability data (i.e., syndromal evidence) than by expert testimony based on case history data (i.e., credibility of anatomically detailed doll evidence). Participant responses did not differ as a function of the strength of the cross-examination of the expert. As expected, women were more likely to respond in a pro-prosecution direction than were men. Implications for the use of expert evidence in child sexual abuse cases are discussed.     

Does Post-identification Feedback Affect Evaluations of Eyewitness Testimony and Identification Procedures?

Two experiments were conducted to test whether post-identification feedback affects evaluations of eyewitnesses. In Experiment 1 (N = 156), evaluators viewed eyewitness testimony. They evaluated witnesses who received confirming post-identification feedback as more accurate and more confident, among other judgments, compared with witnesses who received disconfirming post-identification feedback or no feedback. This pattern persisted regardless of whether the witness’s confidence statement was included in the testimony. In Experiment 2 (N = 161), witness evaluators viewed the actual identification procedure in which feedback was delivered. Instructions to disregard the feedback were manipulated. Again, witnesses who received confirming feedback were assessed more positively. This pattern occurred even when witness evaluators received instructions to disregard the feedback. These experiments are the first to confirm researchers’ assumptions that feedback effects on witnesses translate to changes in judgments of those witnesses.     

When an Alibi Is Not Enough: Judgments of Evidence Needed to Lay Charges in a Burglary Case

Laypersons were asked to assume the role of investigators to explore judgments of what evidence is needed to make an arrest in a criminal investigation when an alibi witness is present. Participants were sensitive to the relationship between the alibi witness and the suspect and were more likely to believe an alibi provided by someone unrelated to the suspect, as evidenced by requests for more physical evidence against the suspect than when the alibi corroborator was a family member. In addition, when presented with contradictory evidence, the age of the alibi witness became an important consideration. Age alone did not impact perceptions of evidence adequacy; however, when an (adult) eyewitness provided testimony that contradicted a child alibi witness, participants demonstrated partiality towards believing the child as evidenced by (a) more requests for physical evidence to be convinced the child was wrong and to arrest the suspect and (b) higher ratings of alibi witness credibility. This effect was not seen when the eyewitness’s testimony contradicted an alibi provided by an adult. The results provide insight for investigators and legal counsel regarding the influence of varying types of alibi witness evidence.     

Effects of preconceptions on deception detection and new answers to why lie-catchers often fail

Abstract

This study investigated the extent to which crediting and discrediting background information, given to observers before they watched three video-taped interviews with the same witness, affected their veracity judgments. Our analyses show that the observers' distribution of truth/lie-judgments were more affected by crediting than discrediting background information. We also mapped the subjective cues given to justify the truth/lie-judgments, and found that the most frequently used cue was whether or not the three statements were consistent over time. In addition, our analysis revealed two types of inter-observer disagreements. One type referred to how different cues were perceived (e.g., forty observers perceived the three statements as being inconsistent over time while an equal number perceived the same three statements as being consistent over time). The second type referred to how different cues were used (e.g., the fact that the witness was perceived as not being confident in his testimony worked against him equally as often as it worked for him).     

Expert Evidence Pertaining to Battered Women: The Impact of Gender of Expert and Timing of Testimony

The present study investigated the impact of two variables relating to general expert testimony pertaining to battered women on juror decision processes. Specifically, the gender of the expert, as well as the timing of the presentation of the testimony, were investigated in a simulated homicide trial involving a battered woman who had killed her abuser. Results indicated that when the expert was female and the testimony was presented prior to the defendant's testimony, jurors' verdicts were more lenient. Moreover, across a range of case judgments, male jurors' perceptions were more favorable to the defendant when the expert was female as opposed to male. On two of the judgments this latter pattern of results was only evidenced when the testimony was presented early as opposed to late. The significance of these findings is discussed.     

The importance of forensic evidence for decisions on criminal guilt

Recent studies have found that the general public perceives forensic evidence to be relatively inaccurate and to involve high levels of human judgement. This study examines how important the general public finds forensic evidence by comparing decisions on guilt and punishment in criminal cases that involve forensic versus eyewitness testimony evidence and examining whether a CSI effect exists. Specifically, this experimental survey study utilized a 2 (crime type: murder or rape) × 4 (evidence type: DNA, fingerprint, victim eyewitness testimony, or bystander eyewitness testimony) ? 1 (no victim testimony for murder scenario) design, yielding seven vignettes scenarios to which participants were randomly assigned. Results indicate that forensic evidence was associated with more guilty verdicts and higher confidence in a guilty verdict. Forensic evidence did not change the expected sentence length and did not generally affect the ideal sentence length. However, for rape, respondents believed that the defendant should receive a longer sentence when forensic evidence was presented but forensic evidence did not alter likely sentence that respondents expected the defendant to receive. The results of this study did not support a CSI effect. Overall, this study suggests that forensic evidence – particularly DNA – has a stronger influence during the verdict stage than the sentencing stage.     

Do pre‐admonition suggestions moderate the effect of unbiased lineup instructions?

We examined the additive and interactive effects of pre‐admonition suggestion and lineup instructions (biased or unbiased) on eyewitness identification rates. Participants watched a mock crime video, completed a target‐absent lineup identification, and completed a retrospective memory questionnaire. Prior to attempting an identification, participants were either exposed or not exposed to pre‐admonition suggestions and received biased or unbiased lineup instructions. The pre‐admonition suggestion indicated that it was likely that the perpetrator was in the lineup (surely, you can pick the perpetrator). The pre‐admonition suggestion increased false identification in the unbiased lineup condition. Furthermore, those who received the pre‐admonition suggestion were more certain in their identifications as well as other testimony‐relevant judgments than were those who did not receive the pre‐admonition suggestion. These results suggest that pre‐lineup suggestion can mitigate the beneficial effects of unbiased lineup instructions.     

Complex scientific testimony: How do jurors make decisions?

Critics of the civil jury system question whether jurors can adequately evaluate complex expert testimony. Based on current models of research in persuasion, we hypothesized that when expert testimony is complex, factors other than content will influence persuasion. Participants, serving as mock jurors, watched a videotaped trial in which two scientists provided evidence on whether PCBs could have caused a plaintiff's illness. The complexity of the expert's testimony and the strength of the expert's credentials were varied in a 2×2 factorial design. After watching the videotape, mock jurors rendered a verdict and completed a number of attitude measures related to the trial. Overall, consistent with our prediction, we found that jurors were more persuaded by a highly expert witness than by a less expert witness, but only when the testimony was highly complex. When the testimony was less complex, jurors relied primarily on the content of that testimony, and witness credentials had little impact on the persuasiveness of the message.     

Confidence inflation in eyewitnesses: Seeing is not believing

Purpose. Confidence inflation in eyewitnesses obscures a useful cue to identification accuracy and affects evaluations of eyewitnesses (e.g., Bradfield & McQuiston, 2004; Jones, Williams, & Brewer, 2008). We examine whether sensitivity to confidence inflation evidence is enhanced by seeing a videotape of the identification procedure. Methods. Participants (N= 131) watched a videotaped trial in which the witness's original confidence statement was presented as part of a previously recorded videotaped identification procedure or read by the witness at trial. In addition, the witness's identification confidence was either consistently high or low at the time of the identification and high at the trial (i.e., it was inflated). Results. Significant interactions demonstrated that confidence inflation evidence factored into judgments of the eyewitness and defendant guilt more strongly in the videotape condition compared with the read condition. Conclusions. The present results support recommendations to collect immediate confidence reports and videotape identification procedures. Using videotape evidence may help innocent defendants convince jurors that the eyewitness's identification is not accurate.     

The Impact of Negative Forensic Evidence on Mock Jurors’ Perceptions of a Trial of Drug-Facilitated Sexual Assault

Legal concerns with regard to the adverse impact of a negative toxicological screening for date-rape drugs in a case of drug-facilitated sexual assault (DFSA) were the focus of a recent Canadian case (R. v. Alouache, 2003). To assess the impact of a negative forensic report, as well as the impact of expert testimony explaining the many factors that may contribute to a negative outcome, participants (N=171) received a written trial stimulus in which the forensic evidence (negative report, negative report plus expert testimony, no negative report and no expert testimony control) and the complainant's beverage consumption (alcohol, cola) were systematically varied. Results indicate that a negative finding in the absence of expert testimony produced greater verdict leniency and more favourable evaluations of the defendant's case. In contrast, no differences were found between the case in which the expert testified and a case in which the negative report and expert testimony were omitted.

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