Educating Jurors about Forensic Evidence: Using an Expert Witness and Judicial Instructions to Mitigate the Impact of Invalid Forensic Science Testimony

Invalid expert witness testimony that overstated the precision and accuracy of forensic science procedures has been highlighted as a common factor in many wrongful conviction cases. This study assessed the ability of an opposing expert witness and judicial instructions to mitigate the impact of invalid forensic science testimony. Participants (N = 155) acted as mock jurors in a sexual assault trial that contained both invalid forensic testimony regarding hair comparison evidence, and countering testimony from either a defense expert witness or judicial instructions. Results showed that the defense expert witness was successful in educating jurors regarding limitations in the initial expert's conclusions, leading to a greater number of not-guilty verdicts. The judicial instructions were shown to have no impact on verdict decisions. These findings suggest that providing opposing expert witnesses may be an effective safeguard against invalid forensic testimony in criminal trials.     

Juror Sensitivity to the Cross-Race Effect

Black and White mock jurors' sensitivity to the cross-race effect was investigated by varying the race of the eyewitness in a simulated murder trial of a Black defendant. Participants heard an audiotape of a trial after which they rendered a verdict and rated the credibility of the witnesses. White participants found the prosecution witnesses (including the eyewitness) more credible, and the defense witness less credible, than did Black participants; they were also more likely to find the defendant guilty. The Black eyewitness was perceived as more credible than was the White eyewitness, but eyewitness race had no effect on verdict. These results are consistent with the literature indicating that jurors of different races reach different verdicts, and also that jurors are relatively insensitive to factors that affect eyewitness testimony, such as the cross-race effect.     

Face-to-Face Confrontation: Effects of Closed-Circuit Technology on Children's Eyewitness Testimony and Jurors' Decisions

The present study was designed to examine effects of closed-circuit technology on children's testimony and jurors' perceptions of child witnesses. For the study, a series of elaborately staged mock trials was held. First, 5- to 6-year-old and 8- to 9-year-old children individually participated in a play session with an unfamiliar male confederate. Approximately 2 weeks later, children individually testified about the event at a downtown city courtroom. Mock juries composed of community recruits viewed the trials, with the child's testimony presented either live in open court or over closed-circuit television. Mock jurors made ratings concerning the child witness and the defendant, and deliberated to reach a verdict. Results indicated that overall, older children were more accurate witnesses than younger children. However, older, not younger children produced more inaccurate information in free recall. Compared to live testimony in open court, use of closed-circuit technology led to decreased suggestibility for younger children. Testifying in open court was also associated with children experiencing greater pretrial anxiety. Closed-circuit technology did not diminish factfinders' abilities to discriminate accurate from inaccurate child testimony, nor did it directly bias jurors against the defendant. However, closed-circuit testimony biased jurors against child witnesses. Moreover, jurors tended to base their impressions of witness credibility on perceived confidence and consistency. Implications for the use of closed- circuit technology when children testify are discussed.     

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.     

Increasing jurors' participation in trials

A field experiment is reported that examines the advantages and disadvantages of two juror participation procedures: Allowing jurors to take notes during the trial, and allowing jurors to direct questions to witnesses. The presence or absence of both procedures was randomly assigned to 34 civil and 33 criminal trials in Wisconsin circuit courts. Following the trials, questinnaires were administered to judges, lawyers, and jurors. Overall, no evidence is found to support the hypotheses that juror notetaking would serve as a useful memory aid, would assist the jury with recall of the judge's instructions, or would increase the jurors' confidence in their verdict. The hypothesis that juror notetaking would increase juror satisfaction with the trial was supported. None of the findings supported the conclusion that juror notetaking was distracting, that notetakers were overly influential during the deliberations, that the jurors' notes were inaccurate, that the notes favored the plaintiff, or that the notes heightened juror disagreement about the trial evidence. It was hypothesized, but not found, that allowing juror questions of witnesses would uncover important issues in the trial and would increase the jurors' satisfaction with the trial procedure. However, juror questions did serve to alleviate juror doubts about the trial testimony, and provided the lawyers with feedback about the jurors' perception of the trial. No evidence was found to support the expectations that juror questions would slow the trial, would upset the lawyers' strategy, or that the question-asking procedure would be a nuisance to the courtroom staff. Furthermore, the lawyers did not appear overly reluctant to object to inappropriate questions from jurors, and jurors did not report being embarassed or angry when their questions were objected to.Dispute Resolution Research Center, Northwestern University     

让尾巴摇狗：美国情态证据实证研究

情态证据指的是在庭审时,被告人或证人等的面部、声音或身体等各部分及其整体上表现出来的能够证明案件真实情况的材料。情态证据至今仍被（西方）法律认可为判断证人可靠性的重要基础,在现代司法中起着至关重要的作用。确保审判者能够观察证人作证时情态的机会,为公开审判（开庭审判）提供了历史的和现代的正当性。在美国司法体系中,陪审团可以合法运用证人席上证人的情态证据;对于证人席外情态证据的使用则在实际上存在,法律上没有形成统一而稳定的规范。法官可以在证据排除、藐视法庭罪、量刑、听证、案件事实判断和陪审团选择程序中使用情态证据。检察官可以在辩诉交易和量刑建议、陪审团候选人＂无因排除＂和审判程序中合理使用情态证据。律师在诉讼过程中不仅从法律意义上,更从诉讼策略意义上运用情态证据。     

Jurors' knowledge of battered women

An increasing number of psychologists with expertise in the area of battered women are participating in the legal system as expert witnesses and occasionally testify on behalf of a battered woman who has injured or killed her partner. Testimony about the battered woman syndrome has been offered to help the jury understand why the defendant reasonably perceived that she was in danger of harm. One of the requirements of expert testimony is that it be beyond the common understanding of the jury. Many commentators assume that jurors are uninformed or misinformed about battered women and, thus, that expert testimony is necessary to educate them. This study evaluated what jurors know about violent relationships. Approximately 300 jurors read scenarios about spousal violence and answered a questionnaire dealing with circumstances surrounding such abuse. Results suggest that on certain dimensions of spousal violence, jurors are aware of empirical research findings. On other dimensions, jurors are less well-informed and could potentially benefit from the testimony of an expert.     

The impact of protective shields and videotape testimony on conviction rates in a simulated trial of child sexual abuse

In Experiment 1 mock jurors watched a videotape simulation of a sexual abuse trial that included a 10-year-old child witness testifying in one of three different modalities: (1) The child testified in court while directly confronting the defendant (open court condition). (2) The child testified in court with a protective shield placed between the child and the defendant (shield condition). (3) The child testified outside the courtroom and the child's testimony was presented to the jury and the defendant on a video monitor (video condition). The mock jurors judged the guilt of the defendant after watching the entire trial. The modality of the child's testimony had no impact on conviction rates. In Experiment 2 subjects watched the same trial that was used in Experiment 1. The trial was stopped immediately after the child testified (the child was the first witness to take the stand), and subjects judged the guilt of the defendant. The modality of the child's testimony had a significant impact on conviction rates. Subjects in the open court condition were more likely to convict the defendant than subjects in the shield and videotape conditions. These findings are relevant to Supreme Court decisions regarding the use of protective devices with child witnesses.     

What Makes Recovered-Memory Testimony Compelling to Jurors?

Little is known about how jurors arrive at verdicts in cases involving recovered memories of childhood sexual abuse. Study 1 investigated mock jurors' reactions to the recovered-memory testimony of an alleged victim when a therapist intervened with hypnosis, suggestion, or symptom management. When a therapist used hypnosis, jurors viewed the victim's recovered-memory testimony as particularly accurate and credible, and favored the victim in their verdicts. In Study 2, mock jurors were presented with a therapist who was sued for allegedly influencing a client's recall of false memories of abuse. In this case, however, jurors viewed therapists who used hypnosis or suggestion as more likely to have created false memories, more responsible for having caused harm, and less competent, and tended not to favor these therapists in their verdicts. We discuss these seemingly contradictory findings in terms of how culturally formed expectancies about hypnosis produce different causal explanations depending on the focus of a trial.     

Expert Testimony Regarding Child Witnesses: Does It Sensitize Jurors to Forensic Interview Quality?

Does expert testimony on forensic interviews with children help adults distinguish between poorly conducted and well-conducted interviews? This study evaluates the effects of social framework expert testimony regarding child witnesses in a case involving allegations of child sexual abuse. A 2 (Expert Testimony: present or absent) × 3 (Child Forensic Interview Quality: poor, typical, or good) × 2 (Child’s Age: 4- or 10-year-old) factorial design was used to examine whether expert testimony is prejudicial or beneficial to jurors (N = 463). The results revealed that, without expert testimony, mock jurors did not consider the forensic interview quality when reaching a verdict. However, with expert testimony, mock jurors were more likely to render guilty verdicts if the interview quality was good versus poor. Further expert testimony increased mock jurors’ knowledge about child witnesses. These findings suggest that expert testimony related to the impact of interview techniques on the reliability of children’s reports may assist fact-finders in evaluating child abuse cases.     

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.     

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.     

Cameras in the courtroom

The present experiment examined some of the key psychological issues associated with electronic media coverage (EMC) of courtroom trials. Undergraduate student subjects served as eitherwitnesses orjurors in one of three types of trials:EMC, in which a video camera was present; conventional media coverage (CMC), in which a journalist was present; or, ano-media control, in which no media representative or equipment was present. Students who served as witnesses first viewed a 5-min videotape of a reenacted armed robbery. Days later, these students testified as witnesses to the crime in front of a jury of peers. Measures assessed the following: witness and juror attitudes toward EMC, witness report and juror perceptions of nervousness and media distraction, juror perceptions of witness testimony, and witnesses' ability to accurately recall aspects of the crime event. Results showed that EMC witnesses and jurors had significantly more favorable attitudes toward EMC than participants in the other two conditions. And, although EMC witnesses and jurors both reported greater witness nervousness, distraction, and awareness than those in the CMC condition, the EMC experience did not impair witnesses' ability to accurately recall the details of the crime or witnesses' ability to communicate effectively. The psychological and legal policy implications of these findings are discussed.     

Hearsay Versus Children's Testimony: Effects of Truthful and Deceptive Statements on Jurors’ Decisions

Researchers and courts are focusing increasing attention on the reliability of children's out-of-court statements, especially in relation to trials of child sexual abuse. The main goal of this study was to investigate the effects of presentation of children's out-of-court statements (e.g., hearsay) on jurors' perceptions of witness credibility and defendant guilt, and on jurors' abilities to reach the truth. Child participants experienced either a mock crime or were coached to say they experienced the crime when in fact they had not. During elaborate mock trials involving community member jurors, children's testimony was presented either: (1) live, (2) on videotape, or (3) via a social worker. Analyses revealed that testimony format directly influenced jurors' perceptions of child and social worker credibility (e.g., children were perceived as less likely to provide false statements if they testified live) as well as jurors' sympathy toward the child, all of which then predicted jurors' confidence in defendant guilt. Jurors had difficulty discerning accurate from deceptive child statements regardless of testimony format. Implications for psychology and the legal system are discussed.     

An analysis of the relationship between jurors' personal attributes and decision making

Using a survey from a jury simulation study, this study examines the relationship between jurors' personal and social attributes and their decision-making behavior. The hypothesis is examined whether personal attributes and socialization of jurors have any significant effect on their decision-making behavior. The analysis suggests that personal and/or social attributes of jurors have little, if any, impact on their decision-making behavior. Instead, jury instruction and information about the matter appear to be major influence contributors. Additionally, evidence presented during the trial and knowledge of law have significant effects upon how jurors decide cases and give verdicts. Author's Note: Suman Kakar, Ph.D., is associate professor at Florida International University, College of Health and Urban Affairs. She conducts research in the areas of juvenile delinquency, child abuse, family dynamics, minorities, and the prevention of violence. She has published two books,Child Abuse and Delinquency (1996) andCriminal Justice Approaches to Domestic Violence (1998).     

Lineup Administrators' Expectations: Their Impact on Eyewitness Confidence

This research focuses on how lineup a administrators influence eyewitnesses' postidentification confidence. What happens to witness confidence when a witness makes an identification that confirms the lineup administrator's expectations; what happens when this expectation is not confirmed? In Experiment 1, participant interviewers (n = 52) administered target-absent photo lineups to participant witnesses (n = 52). The interviewers did not view the simulated crime, but were told the thief's position in the lineup. In every instance this information was false (we used a target-absent lineup). A one-way ANOVA revealed that eyewitness identification confidence was malleable as a function of interviewers' beliefs about the thief's identity. In Experiment 2, participant jurors (n = 80) viewed 40 testimonies of Experiment 1 witnesses (2 participants viewed each testimony). Participant jurors judged all participant witnesses as equally credible despite their varying levels of postidentification confidence.

     

Perceptions of coercion in interrogation: comparing expert and lay opinions

ABSTRACT

When confessions are entered into evidence in criminal courts, issues of coercion and voluntariness are important and often contested matters. Occasionally, defense attorneys proffer expert witnesses to testify about the coercive pressures of an interrogation and the risk of a false confession. Such testimony is often ruled inadmissible on the grounds that it does not inform the jury beyond its common knowledge. In our effort to test this judicial assumption about common knowledge, we surveyed jury-eligible laypeople (n?=?67) and social scientists specializing in interrogation and confessions (n?=?54) regarding their opinions about the coerciveness of prohibited interrogation tactics, maximization techniques, minimization techniques, and suspect risk factors and compared their ratings with a set of independent t tests. Laypeople gave lower ratings to the coerciveness of all sets of items representing interrogation techniques, and lower ratings to the vulnerabilities associated with suspect risk factors, as compared to social science experts. The disparities between laypeople’s and experts’ perceptions of coercion in interrogations demonstrate that such issues are not fully within the common knowledge of prospective jurors, and suggest the need to provide jurors with expert witness guidance when tasked with evaluating confession evidence.