Impact of hypnotic testimony on the jury

In the past decade, the forensic use of hypnosis to enhance the memories of victims, witnesses, and defendants has sharply increased. A great deal of controversy surrounds this issue. Some commentators argue that testimony derived from hypnosis should not be allowed as evidence because of its inherent unreliability and the unduly powerful impact it may have on a jury. In the present research, we used a jury simulation technique to study the impact that a hypnotically refreshed witness has upon jurors' decision making. A major finding is that jurors view hypnotic testimony with a certain amount of skepticism. In some respects, its impact is comparable to that of testimony based on delayed recall, and rarely does it have the impact of testimony from an immediate report. In addition, jurors' judgments about hypnotically refreshed testimony affected the way they evaluated other evidence at trial: Jurors who learned that a prosecution witness had been hypnotized were less believing ofother prosecution witnesses than were jurors not exposed to hypnotic testimony. The forensic application of these findings is discussed.This research was supported by a grant from the National Science Foundation, Law and Social Sciences Program. We thank Jane Goodman, Doug Leber, Bonnie Sawnson, Russ Wade, Karen Guest, Jonna Barsanti, Don Kline, Elaine Sullivan, and David Kuykendall for their help at various stages of the project.     

论专门性问题的诉讼证明

基于我国现行诉讼法关于专门性问题证明的制度缺陷 ,笔者认为 ,应对鉴定人的产生、鉴定活动、鉴定内容和范围的确定以及法庭对专门性问题的审查、判断等问题加以规范和完善 ,允许和吸收其他同行专家参与对专门性问题的证明活动 ,监督和保障专门性问题证明和采信的公开性、科学性、规范性 ,保证证明结果的准确性和公正性。     

Court evaluations of young children's testimony in child sexual abuse cases

Purpose

Prosecutors working with child sexual abuse (CSA) cases involving young children have raised concerns that reliability criteria from the Supreme Court of Sweden are holding children's testimony to impossible standards (e.g., expecting the child's testimony to be long, rich in detail and spontaneous). This study aimed to address these concerns by investigating how District Courts and Courts of Appeal employ said criteria in their testimonial assessments of young child complainants.

Methods

Court documents from District Courts (n = 100) and Courts of Appeal (n = 45) in CSA cases involving 100 children age 7 years and under were analysed with respect to the courts’ testimonial assessments.

Results

Testimonial assessments were more frequently referenced in acquitting verdicts and in cases with evidence of low corroborative value. Richness in detail was the most frequently used reliability criterion, followed by spontaneity. Most criteria were used in favour of the children's testimony. However, the length criterion was typically used against the reliability of the children's testimony.

Conclusions

Our findings confirm prosecutors’ concerns that criteria from the Supreme Court are frequently used in evaluations of young children's testimony. This is troublesome, as some criteria do not correspond to current research on young children's witness abilities. For example, compared to testimony given by older children or adults, testimony provided by a young child is typically not long or rich in detail. We encourage prosecutors to extend their own knowledge on young children's capability as witnesses and present this to the court.     

Impact of Defense-Only and Opposing Eyewitness Experts on Juror Judgments

Previous research shows that expert testimony on eyewitness memory influences mock-juror judgments. We examined the extent to which opposing expert testimony mitigates the impact of defense-only expert testimony. Participants (N = 497) viewed a video-taped trial involving an eyewitness identification and individually rendered verdicts and evaluated the evidence and the experts. We manipulated the Foils (unbiased vs. biased) and Instructions (unbiased vs. biased) of the lineup and Expert Testimony (no expert vs. defense-only expert vs. opposing experts). Expert testimony did not significantly influence juror judgments, but the opposing expert testimony diminished the credibility of the defense expert in the eyes of the jurors. Results point to the need for further research on conditions that qualify the impact of expert testimony.     

Considering forensic science: individual differences,opposing expert testimony and juror decision making

Two experimental studies examined the effect of opposing expert testimony on perceptions of the reliability of unvalidated forensic evidence (anthropometric facial comparison). In the first study argument skill and epistemological sophistication were included as measures of individual differences, whereas study two included scores on the Forensic Evidence Evaluation Bias Scale. In both studies participants were assigned to groups who heard: (1) no expert testimony, (2) prosecution expert testimony, or (3) prosecution and opposing expert testimony. Opposing expert testimony affected verdict choice, but this effect was mediated by perceptions of reliability of the initial forensic expert's method. There was no evidence for an effect on verdict or reliability ratings by argument skill or epistemology. In the second experiment, the same mediation effect was found, however scores on one subscale from the FEEBS and age also affected both verdict and methodological reliability. It was concluded that opposing expert testimony may inform jurors, but perceptions of the reliability of forensic evidence affect verdict, and age and bias towards forensic science influence perceptions of forensic evidence. Future research should investigate individual differences that may affect perception or bias towards forensic sciences under varying conditions of scientific reliability.     

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.     

He‐said–she‐said: Contrast effects in credibility assessments and possible threats to fundamental principles of criminal law

Purpose. Some criminal trials turn on evaluations of credibility of the complainant and the accused. When credibility is based on how a witness testifies, an evaluation of one party should not influence an evaluation of the other party. If credibility evaluations are bidirectional, fundamental principles of criminal law may be offended. Methods. Six hundred and thirty seven undergraduates read a vignette that described a sexual assault (SA) or a motor vehicle accident (MVA). Karen, the complainant in the SA case and bystander witness in the MVA case, was described as 5, 13, or 20 years old. The vignette was a summary of the police investigation and, in three conditions, the trial. Trial information was manipulated in one of three ways: no information concerning how Karen testified, Karen's testimony was described positively (pro‐prosecution), or described negatively (anti‐prosecution). Participants then rated the perceived credibility of Karen and the accused (Bob) and the probability that Bob was guilty. Results. Karen was viewed more positively in the pro‐prosecution condition and more negatively in the anti‐prosecution. When Karen was judged to be less credible, Bob was rated as more credible and less likely to be guilty. When Karen was seen as more credible, Bob was viewed as more likely to be guilty. Conclusions. This bidirectional effect that the manner in which the prosecution witness testified affected perceptions of the accused and probability of guilt, in certain circumstances, may compromise fundamental principles of criminal law and be a reversible error. We offer possible solutions for future empirical testing.     

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.     

法理学视角下的刑事证人作证制度立法问题研究

刑事证人作证制度立法存在问题是影响证人出庭作证的最主要原因。从法理学视角来看,这些问题表现为违背法制的统一性,法律的调整机制远未建立,立法技术欠缺科学性等,因此必须在刑事诉讼法再修订时予以完善,使证人愿意出庭作证。     

The impact of general versus specific expert testimonyand eyewitness confidence upon mock juror judgment

Subjects (n=128) initially viewed an eyewitness of high or low confidence. Subsequently, participants viewed a psychologist who gave either espert testimony on the unreliability of eyewitness identification, specific expert testimony, or no expert (control) testimony. Subjects viewing expert testimony believed the eyewitness identified the gunman significantly less often, gave the defendant lower guilt ratings, estimated a lower general percentage of correct identifications under similar circumstances, estimated a lower percentage of general accurate eyewitness testimony, and gave significantly lower ratings to the belief that one can generally tell from eyewitness confidence whether an eyewitness is accurate than subjects in control conditions. Significant differences were also obtained between general and specific expert testimony. Participants viewing specific expert testimony estimated lower general percentages of correct identifications under the circumstances of the crime and reported relying more upon the psychologist's testimony than subjects viewing general expert testimony. Additionally, subjects viewing general expert testimony had significantly less confidence in their gunman vs. innocent person decision than subjects in specific testimony or control conditions. Subjects who viewed the high confidence eyewitness decided that the eyewitness correctly identified the gunman more often, gave the defendant higher guilt ratings, and estimated the general percentage of accurate eyewitness testimony to be significantly higher than jurors in low eyewitness confidence groups. The finding that jurors may continue to rely on eyewitness confidence to gauge the accuracy of the witness even after viewing expert testimony is discussed.     

Accuracy,confidence and consistency in repeated recall of events

Abstract

In legal practice, both confidence and consistency of the testimony of eyewitnesses are often used as indicators for accuracy, but their usefulness has been questioned. The present study was designed to determine the relationship between accuracy, confidence and consistency in episodic memory. After viewing a video of a complex series of events, one group of participants was given an initial cued recall test after one week, and repeated recall tests after three and five weeks. A second group of participants was tested after three and five weeks, and a third group was tested only once after five weeks. Accuracy and confidence (at least for incorrect answers) decreased with longer initial retention intervals, but there was no decrease in either accuracy or confidence when recall was repeated. Repeated testing also did not lead to confidence inflation. Correlations between accuracy, confidence and consistency varied from medium to large. Inconsistencies were mainly caused by forgetting and reminiscence. These inconsistencies were recalled almost as accurately as consistently recalled information.     

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.     

Effects of psychopathy and violence risk testimony on mock juror perceptions of dangerousness in a capital murder trial

The recent introduction of the Psychopathy Checklist-Revised (PCL-R) into the sentencing phase of capital murder trials has heightened concerns about the potentially prejudicial impact of such information on jurors, who might give disproportionate weight to this diagnosis when determining whether a defendant is a “continuing threat to society”. To investigate this issue, 238 undergraduates read a case summary based on US v. Barnette ( ), in which prosecution testimony was presented regarding the presence of a mental disorder (psychopathy, psychosis, or no disorder). Compared to the “no disorder” condition, participants rated psychopathic defendants as more likely to be violent in the future, even though testimony related to level of risk (high or low) was held constant. The difference in perceived dangerousness across the psychopathy and no disorder groups was particularly pronounced when the experts described the defendant as being at low risk. A similar pattern of effects was noted for the psychosis condition, suggesting that the impact of mental disorder testimony on perceptions of dangerousness may not necessarily be specific to the PCL-R.     

Assessing Testimonial Evidence in Asylum Proceedings: Guiding Standards from the International Criminal Tribunals

Although credibility determinations rest at the core of refugeeprotection, international refugee law has failed to developa body of evidentiary principles that is tailored to the uniquedimensions of the testimony of those seeking asylum. This articleexamines recent developments in assessing oral testimony ininternational criminal law. International criminal law judges,like national asylum adjudicators, must transcend geographic,linguistic, cultural, educational and psychological barriersin order to assess the credibility of testimony. As a result,these new international courts have developed a body of principlesof international evidence law for assessing the testimony ofalleged victims of, and witnesses to, human rights abuses. Currentsocial science research on the asylum procedures in severaljurisdictions reveals that asylum decision makers often failto adapt the determination process to account for the realitiesof refugees presenting their cases in legal fora, directingproceedings with a ‘presumptive skepticism’ of claims.It is argued that the nuanced and rigourous model for the assessmentof the testimonial evidence of alleged victims and witnessesof human rights abuses in war crimes trials introduces effectiveinternational norms for the assessment of credibility in asylumproceedings.     

Barring ultimate issue testimony

This research focuses on one of the major changes wrought by the Insanity Defense Reform Act of 1984: the exclusion of expert mental health testimony on the “ultimate issue,” that is, testimony specifically addressing the expert's opinion that the defendant is sane or insane. Subjects in this research were presented with 1 of 10 variants of an insanity case in which experts testified for the defense, prosecution, both, or neither. The testimony was at one of three levels: diagnostic only, penultimate issue, or ultimate issue. Results showed that level of testimony had no effect on the verdict pattern. There was evidence to suggest that this effect may occur because jurors infer, and/or mistakenly recall, higher levels of expert testimony than was actually presented to them. In addition, general and specific constructs (Finkel & Handel, 1989) that predict verdict yieldedR ² values from .500 to .668 and were not significantly affected by the level of expert testimony. Implications of these findings are discussed.     

The Use of Religion in Death Penalty Sentencing Trials

Both prosecutors and defense attorneys have presented religious appeals and testimony about a defendant's religious activities in order to influence capital jurors' sentencing. Courts that have objected to this use of religion fear that religion will improperly influence jurors' decisions and interfere with their ability to weigh aggravators and mitigators. This study investigated the effects of both prosecution and defense appeals. Prosecution appeals did not affect verdict decisions; however, use of religion by the defense affected both verdicts and the weighing of aggravators and mitigators. These results could be due to differences in perceived sincerity and remorse that are conveyed in the various appeals.