Expert evidence and hearsay

In upholding the admission of expert evidence, some courts have held that hearsay information conveyed via an expert may be admitted as long as the jury is instructed to ignore the facts asserted in the hearsay statements and to use the information only for determining the weight to attribute to the expert's opinion. Results of a mock juror simulation indicated that although hearsay elements conveyed via an expert were perceived as less likely compared to a condition in which the information was independently admitted at trial, it was not completely ignored by the jurors. Further, the findings tended to suggest that the impact of the hearsay on verdict decisions operated primarily by influencing evaluations regarding the likelihood of the hearsay events as opposed to judgments regarding the expert testimony.     

Meeting a Forensic Podiatry Admissibility Challenge: A Daubert Case Study

This article is an introduction to the United States Supreme Court's standard of admissibility of forensic evidence and testimony at trial, known as the Daubert standard, with emphasis on how this standard applies to the field of forensic podiatry. The author, a forensic podiatrist, provided law enforcement with evidence tying a bloody sock‐clad footprint found at the scene of a homicide to the suspect. In 2014, the author testified at a pretrial hearing, known as “a Daubert hearing,” to address the admissibility of this evidence in court. This was the first instance of forensic podiatry being the primary subject of a Daubert hearing. The hearing resulted in the court ordering this evidence admissible. The expert's testimony contributed to the suspect's conviction. This article serves as a reference for forensic podiatrists and experts in similar fields that involve impression evidence, providing evidentiary standards and their impact on expert evidence and testimony.     

Can experts help jurors to evaluate eyewitness evidence? A review of eyewitness expert effects

Courts occasionally permit psychologists to present expert evidence in an attempt to help jurors evaluate eyewitness identification evidence. This paper reviews research assessing the impact of this expert evidence, which we argue should aim to increase jurors' ability to discriminate accurate from inaccurate identifications. With this in mind we identify three different research designs, two indirectly measuring the expert's impact on juror discrimination accuracy and one which directly assesses its effect on this measure. Across a total of 24 experiments, three have used the superior direct methodology, only one of which provides evidence that expert testimony can improve jurors' ability to discriminate between accurate and inaccurate eyewitness identifications.     

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.     

Jurors' use of probabilistic evidence

Mock jurors' use of probabilistic evidence was examined in a fractional factorial design manipulating 7 variables: strength of nonstatistical evidence; quantification of nonstatistical evidence; strength of statistical evidence; combination of 2 pieces of statistical evidence; instruction in use of Bayes' theorem; and presentation of fallacies (both prosecutor's and defense attorney's) concerning use of statistical evidence. One hundred eighty-nine subjects viewed 1 of 16 videotapes presenting a condensed mock trial. Subjects completed dependent measures after each of 4 witnesses and at the end of trial. The strength of both nonstatistical and probabilistic evidence affected verdicts; the other manipulations did not. Overall, subjects slightly underused the probabilistic evidence, as compared to their individualized Bayesian norms, and subjects did not succumb to fallacies. However, subjects greatly varied in over-or underutilization, even after Bayesian instruction. Future research should examine use of weak nonstatistical evidence, and should test different probabilistic instructions.     

专家证据的价值与我国司法鉴定制度的修改

随着科学技术的飞速发展,专家证据在诉讼中发挥着越来越重要的作用。在英美法系国家,专家证据制度在专家证人资格规定上的广泛性和选任上的自由性,使其在适用上具有灵活性和实用性的特点,其详细而完备的专家证据可采性规则,更是司法经验的积累与法官智慧的结晶。英美法系国家的专家证据制度和大陆法系的鉴定制度,在近些年的改革中呈现出共同的趋向,如启动程序的多样化、过错责任的严格化和庭审对抗的强化,这为完善我国司法鉴定制度、准确适用新刑诉法中有关专家辅助人的规定以及充分发挥专家证据的作用开启了新的思路。面对我国司法鉴定中依然相当混乱的鉴定主体问题,构建鉴定人、专家顾问和专家辅助人三位一体的司法鉴定主体格局,或许是一条比较合理可行的出路。     

Inducing jurors to disregard inadmissible evidence: A legal explanation does not help

Three experiments investigated mock jurors' ability to disregard inadmissible prior conviction evidence and hearsay. In Experiments 1 and 2, college students listened to an audiotape enacting a theft trial. The critical evidence favored the prosecution and was objected to by the defense. In three different conditions the judge either ruled the evidence admissible, ruled it inadmissible, or ruled it inadmissible and explained the legal basis for the ruling. In a fourth condition no critical evidence was presented. The critical witness' credibility was also manipulated. With prior conviction evidence but not hearsay the legal explanation “backfired.” In addition, the critical witness' credibility did not affect subjects' ability to disregard inadmissible evidence. The results of Experiment 3 suggest that the legal explanation may have affected the use of hearsay and prior conviction evidence differently because of subjects' dissimilar preconceptions of the fairness of using the two evidence items to assess guilt.     

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.     

The biasing impact of pretrial publicity on juror judgments

This study examines three previously unexplored aspects of the biasing impact of pretrial publicity. First, this study tests the differential effects of several different types of pretrial publicity on juror decision making. Second, this study explores the impact the presentation of trial evidence has on biases created by pretrial publicity. Finally, the study explores the psychological processes by which pretrial publicity effects may operate. Results indicate that pretrial publicity, particularly negative information about the defendant's character, can influence subjects' initial judgments about a defendant's guilt. This bias is weakened, but not eliminated by the presentation of trial evidence. Character pretrial publicity, and both weak and strong inadmissible statements appear to operate by changing subjects' initial judgments of the defendant's guilt. This initial judgment then affects the way subjects assess the evidence presented in the trial and the attributions they make about the defendant. Prior record pretrial publicity appears to have its effects by influencing subjects' inferences about the criminality of the defendant and this is related to posttrial judgments.     

Thirty Years of Social Science in Supreme Court Criminal Cases*

The Supreme Court early took note of extralegal, “social science” materials in Muller v. Oregon (1908), and a half-century later made specific reference to social science authorities in the famous footnote 11 of Brown v. Board of Education (1954). Since Brown, much has been written about the Supreme Court's use of social science research evidence, but there has been little systematic study of that use. Those writing on the subject commonly focus on areas of law such as jury size, where social science has been used, and have generally assumed that social science information has been utilized in Supreme Court decisions with increasing regularity. Surprisingly little is known, however, about either the justices' baseline use of social science authorities, or many other aspects of their uses of social science information. The focus here is on the citation of social science research evidence in a sample of 240 criminal cases decided during the 30 years between the Supreme Court's 1958 and 1987 Terms. The resulting portrait contributes to a fuller understanding of the justices' use of social science materials, and may ultimately help promote more effective utilization of social science research evidence in Supreme Court decisions.     

Mock jurors’ perceptions of a child witness: the impact of the presence and/or intervention of a registered intermediary during cross-examination

ABSTRACT

In recent years Registered Intermediaries (RIs) have been involved in facilitating communication in children's investigative interviews and trial proceedings. Their presence and interventions are generally deemed to have a positive impact on child engagement, but their impact on jury appraisal of evidence, during cross-examination is unclear. This study addressed this issue in a more ecologically valid context than that previously used. Adult mock juror participants (N?=?217) watched a video-recording of a mock cross-examination of a child witness in which a RI was present or absent, and in which RI type interventions were either included or omitted. The participants rated the quality of the cross-examination and the child's responses in relation to child credibility, child understanding, legal professional's behaviour, and trial progression. Findings indicated that RI presence or absence, and inclusion or omission of interventions had no effect on mock juror ratings. However, an interaction between these variables demonstrated that mock jurors rated trial progression towards a guilty verdict according to which court professional did, or did, not intervene. The findings also demonstrated that mock jurors based their assessment of trial progression towards a guilty verdict on the evidence presented, and that child understanding per se was irrelevant.     

Extending the Confusion About Bayes

In R v T [2010] EWCA Crim 2439, [2011] 1 Cr App Rep 85, the Court of Appeal indicated that ‘mathematical formulae’, such as likelihood ratios, should not be used by forensic scientists to analyse data where firm statistical evidence did not exist. Unfortunately, when considering the forensic scientist's evidence, the judgment consistently commits a basic logical error, the ‘transposition of the conditional’ which indicates that the Bayesian argument has not been understood and extends the confusion surrounding it. The judgment also fails to distinguish between the validity of the relationships in a formula and the precision of the data. We explain why the Bayesian method is the correct logical method for analysing forensic scientific evidence, how it works and why ‘mathematical formulae’ can be useful even where firm statistical data is lacking.     

保险人明确说明义务批判

保险合同法可以体系化地解读为意思自治、给付均衡与合理期待三个核心原则的组合。立法者希望籍说明义务来消减信息不对称,贯彻意思自治。但在建构制度规范时,并未考虑信息传送方的履行成本,对信息接收方的识别成本与关注焦点也存在认识误区。这种过度理想化的设计已被实践证明是失败的。立法应废止实质性的明确说明义务,代之以形式化的信息提供义务。对于意思自治的不足,可以通过提升给付均衡度和更有效保障被保险人对获取保险产品的合理期待加以填补。     

Is the Expert Admissibility Game Fixed?: Judicial Gatekeeping of Fire and Arson Evidence

Anecdotal evidence claims that in criminal cases, trial judges admit the prosecution's expert witnesses more readily than the defendants', and in civil cases the reverse is true; judges exclude plaintiffs' experts more often than civil defendants' experts. This occurs despite the fact that, with few exceptions, the same rules of admissibility apply to all parties and, in most jurisdictions, across criminal and civil cases. This article empirically tests this differential by reviewing judicial decisions to admit or exclude evidence holding the type of expert testimony constant, fire and arson evidence, across criminal and civil cases in the United States. The study examines the admissibility of fire and arson investigation experts in criminal and civil cases across all legal parties in fifty‐seven federal and state opinions in the United States. The findings offer empirical support of a bias in criminal cases and in civil cases which present expert witnesses at trial, and is less pronounced, but still evident, on appeal. Specifically, the role of the party that offers the evidence has a profound effect on whether arson evidence is admitted, even when factors around the judge's political affiliation, attorney experience, expert qualifications, and rules of evidence are taken into account.     

Mock jurors' perceptions of identifications made by intoxicated eyewitnesses

Abstract

Psychology research has generally neglected intoxicated eyewitnesses. The current study addressed this need by exploring mock jurors' perceptions of intoxicated witnesses. Undergraduate participants read summarized sexual or aggravated battery cases in which either the victim or a bystander identified the defendant under varying intoxication levels. They answered questions about the case and provided verdicts. Participants were sensitive to the effect that intoxication may have on witnesses' cognitive ability, but not to varying degrees of intoxication. Neither the role of the eyewitness nor the type of crime committed had an effect on perceptions of witness impairment. Participants' perceptions of witness impairment informed identification credibility ratings, and credibility assessments affected verdicts. Impairment and credibility ratings fully mediated intoxication's effect on verdicts. Unlike much prior research, our results suggest that mock jurors can consider potentially important witness information when rendering verdicts.     

The adequacy of China's responses to wrongful convictions

This paper examines a series of reforms that followed the discovery of high-profile wrongful convictions in China since 2005. There have been two waves of criminal justice reforms to prevent future wrongful convictions and to improve China's criminal justice system more generally. But it will be suggested in this paper that China's responses are inadequate because they allow traditional police and judicial practices that will lead to future wrongful convictions to continue. Further reforms will be suggested. First, police interrogations should be fully recorded, and the entire recording should be played back at trial. Second, the role of the defense counsel should be expanded. The use of state secrets as evidence against the accused should be curtailed. The close cooperation between the police, procuratorates and judiciary in the criminal justice should be counteracted by the creation of an independent body to review all serious convictions. Finally, the Chinese criminal justice has proven itself not safe enough to allow the broad use of capital punishment as a punishment for non-violent offences and at the very least, the immediate execution of prisoners who lose their final appeal must be abolished.     

Statistical Inference and Forensic Evidence: Evaluating a Bullet Lead Match

This experiment tested the ability of undergraduate mock jurors (N=295) to draw appropriate conclusions from statistical data on the diagnostic value of forensic evidence. Jurors read a summary of a homicide trial in which the key evidence was a bullet lead "match" that was either highly diagnostic, non-diagnostic, or of unknown diagnostic value. There was also a control condition in which the forensic "match" was not presented. The results indicate that jurors as a group used the statistics appropriately to distinguish diagnostic from non-diagnostic forensic evidence, giving considerable weight to the former and little or no weight to the latter. However, this effect was attributable to responses of a subset of jurors who expressed confidence in their ability to use statistical data. Jurors who lacked confidence in their statistical ability failed to distinguish highly diagnostic from non-diagnostic forensic evidence; they gave no weight to the forensic evidence regardless of its diagnostic value. Confident jurors also gave more weight to evidence of unknown diagnostic value. Theoretical and legal implications are discussed.