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.     

Polygraph Testimony and Juror Judgments: A Comparison of the Guilty Knowledge Test and the Control Question Test1

The present experiment investigated the impact of the Control Question Test (CQT) and the Guilty Knowledge Test (GKT) on the verdicts of mock jurors. Although studies have indicated that polygraph evidence has little influence on jurors' verdicts (Cavoukian & Heselgrave, 1980; Spanos, Myers, Dubreuil, & Pawlak, 1992–1993), no research has previously distinguished between the different types of polygraph tests and their impact on juror verdicts. In the present study, jurors were shown a videotape of a simulated rape-murder trial that contained either CQT polygraph evidence, GKT polygraph evidence, or no polygraph evidence. No differences were found among the 3 conditions for either jury verdicts or individual juror verdicts, and jurors tended to rate both forms of polygraph testimony below other forms of equally suspect evidence, such as eyewitness testimony, in its influence on their decision-making process.     

Expert testimony in child sexual abuse cases: The effects of evidence,coherence and credentials on juror decision making

Psychological experts have been used increasingly to testify in child sexual abuse cases, yet little research has investigated what specific factors make experts effective. This study examined the potential effects that credentials, evidence strength and coherence may have on juror decision making. Sixty‐four mock jurors read cases of child sexual abuse, followed by experts' testimony and rated guilt of the defendant, effectiveness of the expert testimony and credibility of the victim. Evidence strength and coherence of the testimony affected all dependent variables, and the interaction was significant. Guilt ratings of the defendant were lower and the victim was rated as less credible when both evidence strength and coherence were low. The credentials of the expert, however, had negligible impact. These findings indicate that experts can be effective and impact jurors when testimony is either high in coherence or high in evidence. Copyright © 2009 John Wiley & Sons, Ltd.     

The Effect of Acknowledging Mock Jurors' Feelings on Affective and Cognitive Biases: It Depends on the Sample

An intervention designed to correct affective and cognitive biases was tested in the context of a civil commitment hearing of a sexually violent predator. Potential differences between a college student mock jury sample and a more representative, juror venire sample in reaction to these bias correction interventions were explored. In the first of two experiments, undergraduate mock jurors (n = 130) demonstrated a leniency effect when the sex offender's attorney acknowledged jurors' emotional reactions and motivated them to thoughtfully weigh the evidence. The second experiment failed to replicate these findings with a more ecologically valid sample (n = 300). Several differences between samples were found: representative jurors, as opposed to undergraduates, were sensitive to differences between pure clinical and actuarial expert testimony; and measures of intrinsic cognitive effort predicted verdicts for undergraduates, but not for representative jurors. Copyright © 2011 John Wiley & Sons, Ltd.     

How effective are the cross-examination and expert testimony safeguards? Jurors' perceptions of the suggestiveness and fairness of biased lineup procedures

Mock jurors (N = 800) viewed a videotaped trial that included information about a lineup identification procedure. Suggestiveness of the eyewitness identification procedure varied in terms of foil, instruction, and presentation biases. Expert testimony regarding the factors that influence lineup suggestiveness was also manipulated. Criteria included juror ratings of lineup suggestiveness and fairness, ratings of defendant culpability, and verdicts. Jurors were sensitive to foil bias but only minimally sensitive to instruction and presentation biases. Expert testimony enhanced juror sensitivity only to instruction bias. These results have implications for the effectiveness of cross-examination and expert testimony as safeguards against erroneous convictions resulting from mistaken identifications.     

The effects of rational and experiential information processing of expert testimony in death penalty cases

Past research examining the effects of actuarial and clinical expert testimony on defendants' dangerousness in Texas death penalty sentencing has found that jurors are more influenced by less scientific pure clinical expert testimony and less influenced by more scientific actuarial expert testimony (Krauss & Lee, 2003; Krauss & Sales, 2001). By applying cognitive-experiential self-theory (CEST) to juror decision-making, the present study was undertaken in an attempt to offer a theoretical rationale for these findings. Based on past CEST research, 163 mock jurors were either directed into a rational mode or experiential mode of processing. Consistent with CEST and inconsistent with previous research using the same stimulus materials, results demonstrate that jurors in a rational mode of processing more heavily weighted actuarial expert testimony in their dangerousness assessments, while those jurors in the experiential condition were more influenced by clinical expert testimony. The policy implications of these findings are discussed.     

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.     

Beliefs about factors affecting the Reliability of eyewitness testimony: A Comparison of judges,jurors and the general public

We surveyed 164 members of the juror pool of the Court of Appeal and a representative sample of 1000 adult Norwegians without juror experience, about their knowledge and beliefs about eyewitness testimony, and compared their answers to a prior survey of Norwegian judges. Although the judges were somewhat more knowledgeable than jurors and the general public, all groups had limited knowledge of eyewitness testimony. Juror experience, in terms of number of times serving as juror, did not correlate with eyewitness knowledge. Consistent with this finding, the knowledge scores of the jurors were similar to the scores of the general public, tested with an abridged seven‐item version of the questionnaire. Comparisons with the results of surveys conducted in the US, indicate similar levels of knowledge among law professionals and jurors in the two countries. Increasing the knowledge of eyewitness testimony among the principal participants in the judiciary system may be an important component of the solution to eyewitness error. Copyright © 2009 John Wiley & Sons, Ltd.     

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.     

Speech style and occupational status affect assessments of eyewitness testimony

This study examined how speech style and occupational status affect mock jurors' assessments of eyewitness testimony. Mock jurors (n = 120) watched a video of a man testifying about witnessing an attempted robbery. The eyewitness exhibited either a powerless or powerful speech style and reported either a high or low (or no) status occupation during his testimony. Results indicated that high occupation status and powerful speech style led to more favorable evaluations of the eyewitness's testimony and of the case against the defendant than powerless speech style and low/no occupation status. Implications of these results on considerations of eyewitness testimony and future research are discussed.     

Effects of Eyewitness Evidence on Plea-Bargain Decisions by Prosecutors and Defense Attorneys1

The present experiment tested the relative impact of two types of eyewitness evidence (identification and non identification) on plea-bargain decisions by prosecutors and defense attorneys. A hypothetical case involving a robbery was mailed to three prosecutors and three defense attorneys in each of 47 states. The subjects were randomly assigned to receive a case in which an eyewitness claimed: (a) the defendant was the criminal (identification), (b) the defendant was not the criminal (non identification), or (c) it was not possible to tell whether the defendant was the criminal (control). Similar to findings with jurors, both prosecutors and defense attorneys underutilized the non identification information in making their plea-bargain decisions. In the case of the prosecutors, there was evidence that the underutilization of eyewitness non identification was at least partially mediated by the prosecutors' predictions of juror reaction to the evidence.     

Understanding pretrial publicity: predecisional distortion of evidence by mock jurors

Prejudicial pretrial publicity (PTP) constitutes a serious source of juror bias. The current study examined differences in predecisional distortion for mock jurors exposed to negative PTP (N-PTP) versus nonexposed control participants. According to work by K. A. Carlson and J. E. Russo (2001), predecisional distortion occurs when jurors bias new evidence in favor of their current leading party (prosecution or defense) rather than evaluating this information for its actual probative properties. Jury-eligible university students (N=116) acted as jurors in a mock trial. Elevated rates of guilty verdicts were observed in the N-PTP condition. Predecisional distortion scores were significantly higher in the N-PTP condition and reflected a proprosecution bias. The effect of prejudicial PTP on verdict outcomes was mediated by predecisional distortion in the evaluation of testimony. Results are discussed in relation to motivated decision making and confirmation biases.     

How jurors use and misuse character evidence

The Federal Rules of Evidence allow defendants to offer testimony about their good character, but that testimony can be impeached with cross-examination or a rebuttal witness. It is assumed that jurors use the defense's character evidence (CE) to form guilt and conviction judgments but use impeachment evidence only to assess the character witness's credibility. Two experiments tested these assumptions by presenting mock jurors with various forms of CE and impeachment. Participants made trait ratings for the character witness and defendant and guilt and conviction judgments. Positive CE did not affect guilt or conviction judgments, but cross-examination caused a backlash in which judgments were harsher than when no CE was given. Using path analysis, the authors tested a model of the process by which CE and impeachment affect defendant and witness impressions and guilt and conviction judgments. Implications for juror decision making are discussed.     

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.     

A qualitative analysis of mock jurors' deliberations of linkage analysis evidence

Evidence about a suspect's behavioural similarity across a series of crimes has been presented in legal proceedings in at least three different countries. Its admission as expert evidence, whilst still rare, is becoming more common thus it is important for us to understand how such evidence is received by jurors and legal professionals. This article reports on a qualitative analysis of mock jurors' deliberations about expert linkage analysis evidence. Three groups of mock jurors (N = 20) were presented with the prosecution's linkage analysis evidence from the USA State v. Fortin I murder trial and expert evidence for the defence constructed for the purposes of the study. Each group was asked to deliberate and reach a verdict. Deliberations were video‐recorded and subject to thematic content analysis. The themes that emerged were varied. Analysis suggested that the mock jurors were cautious of the expert evidence of behavioural similarity. In some cases they were sceptical of the expert. They articulated a preference that expert opinion be supported using statistics. Additional themes included jurors having misconceptions concerning what is typical offender behaviour during rape which suggests there is a need for expert linkage analysis evidence regarding behavioural similarities and the relative frequencies of crime scene behaviours. Copyright © 2010 John Wiley & Sons, Ltd.     

Effects of Victim and Defendant Race on Jurors' Decisions in Child Sexual Abuse Cases1

We examined the influence of victim and defendant race, victim age, juror gender, and juror prejudice on jurors' decisions in child sexual abuse cases. In Experiments 1 and 2, mock jurors judged Black and Hispanic child victims to be more responsible for their sexual abuse than White victims. In Experiment 2, jurors assigned more guilt to defendants in cases involving victims and perpetrators of the same race compared to different races. Experiment 3 illustrated that laypeople believe same‐race cases to be more plausible generally. Experiment 2 revealed that high‐prejudiced White mock jurors made no more racially biased judgments than low‐prejudiced mock jurors. Finally, women were generally more pro‐victim in their case judgments than were men, and older victims were disadvantaged compared to younger victims in terms of perceived credibility and responsibility, and their cases were less likely to draw convictions.