1,720,995 research outputs found
How signature complexity affects expert and lay ability to distinguish genuine, disguised and simulated signatures
This study examined how variations in signature complexity affected the ability of forensic document examiners (FDEs) and laypeople to determine whether signatures are authentic or simulated (forged), as well as whether they are disguised. Forty-five FDEs from nine countries evaluated nine different signature comparisons in this online study. Receiver Operating Characteristic (ROC) analyses revealed that FDEs performed in excess of chance levels, but performance varied as a function of signature complexity: Sensitivity (the true-positive rate) did not differ much between complexity levels (i.e., 65% vs. 79% vs. 79% for low vs medium vs high complexity), but specificity (the true-negative rate) was the highest (95%) for the medium complexity signatures and lowest (73%) for low complexity signatures. The specificity of high-complexity signatures (83%) was between these values. The sensitivity for disguised comparisons was only 11% and did not vary across complexity levels. One hundred-one novices also completed the study. A comparison of the area under the ROC curve (AUCs) revealed that FDEs outperformed novices in medium and high-complexity signatures but not low-complexity signatures. Novices also struggled to detect disguised signatures. While these findings elucidate the role of signature complexity in lay and expert evaluations, the error rates observed here may differ from those in forensic practice due to differences in the experimental stimuli and circumstances under which they were evaluated. This investigation of the role of signature complexity in the evaluation process was not intended to estimate error rates in forensic practice.This article is published as Scurich, Nicholas, Miriam Angel, Hal Stern, and William C. Thompson. "How signature complexity affects expert and lay ability to distinguish genuine, disguised and simulated signatures." Journal of Forensic Sciences 69, no. 6 (2024): 2159-2170. https://doi.org/10.1111/1556-4029.15605. Posted with permission of CSAFE.Center for Statistics and Applications in Forensic Evidence (CSAFE), Grant/Award Number: 70NANB15H176 and 70NANB20H01
Judging Firearms Evidence
Firearms violence results in hundreds of thousands of criminal investigations each year. To try to identify a culprit, firearms examiners seek to link fired shell casings or bullets from crime scene evidence to a particular firearm. The underlying assumption is that firearms impart unique marks on bullets and cartridge cases, and that trained examiners can identify these marks to determine which were fired by the same gun. For over a hundred years, firearms examiners have testified that they can conclusively identify the source of a bullet or cartridge case. In recent years, however, research scientists have called into question the validity and reliability of such testimony. Judges have also viewed such testimony with increased skepticism, especially after the Supreme Court set out standards for screening expert evidence in Daubert v. Merrell Dow Pharmaceuticals, Inc.
In this Article, we detail over a century of caselaw and examine how judges have engaged with the changing practice and scientific understanding of firearms comparison evidence. We first describe how judges initially viewed firearms comparison evidence skeptically and thought jurors capable of making firearms comparisons themselves—without an expert. Next, judges embraced the testimony as comparison experts offered more specific and aggressive claims, and the work spread nationally. Finally, we explore the modern era of firearms caselaw and research, with an explosion of reported judicial decisions. Judges increasingly express skepticism and adopt a range of approaches to limit in-court testimony by firearms examiners. We conclude by examining lessons regarding the gradual judicial shift towards a more scientific approach towards expert testimony. The more-than-a-century-long arc of judicial review of firearms evidence in the United States suggests that over time, scientific research can displace tradition and precedent to improve the quality of justice.The following is published as Garrett, Brandon L. and Tucker, Eric and Scurich, Nicholas, Judging Firearms Evidence (February 3, 2023). Duke Law School Public Law & Legal Theory Series No. 2023-10, Available at SSRN: https://ssrn.com/abstract=4325329 or http://dx.doi.org/10.2139/ssrn.4325329. Posted with permission of CSAFE
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Venire Jurors' Ability to Detect and Willingness to Disclose Bias
The legal system relies on voir dire to ensure the Sixth Amendment guarantee of an impartial jury. This dissertation tests the assumptions of voir dire that venire jurors 1.) can identify their biases accurately and 2.) will report them honestly. It was proposed that venire jurors would underreport their bias. As a result, we hypothesized that a significant proportion of venire jurors who claim that they are impartial would be inaccurate. The present study sought to disentangle whether the jurors are inaccurate because they are unaware of their bias or unwilling to admit it. First, it was hypothesized that increasing participant’s privacy during voir dire would increase their disclosures of bias. However, it was also hypothesized that increasing venire juror’s candidness would not increase the accuracy of their self-reports of bias. That is, we expected to find evidence that jurors underreport bias because they lack awareness of it. The present study was conducted at the Orange County Superior Courthouse with 382 venire jurors. An anti-defendant bias was induced experimentally in a sample of the participants through exposure to pretrial publicity (PTP). The participants then completed a mock trial. During voir dire, participants were asked about their ability to be impartial. Participants exposed to PTP were randomly assigned to complete voir dire either through an in-person interview or a paper-and-pencil questionnaire. Then the participants read a case summary and rendered a verdict. Last, participants completed a post-verdict questionnaire assessing how they thought the PTP affected their verdict. The data revealed that the majority of PTP-exposed venire jurors (70%) maintained that they were not biased. However, privacy did not influence their self-reports of bias, revealing no support for the hypothesis that venire jurors systematically underreport bias. Further, the findings did not support the hypothesis that venire jurors’ self-reports are inaccurate. Participants who said that they were biased were significantly more likely to convict (48%) compared to those who said that they were impartial (21%). Participant’s accuracy also did not vary as a function of their level of privacy during voir dire. Overall, these findings suggest that venire jurors can and do provide accurate self-reports of pretrial publicity bias
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Juror Perceptions of Incentivized Informant Testimony
Informants are an integral part of the American criminal justice system. However, relatively little research has been done on nearly all aspects of informant use, from how they are recruited and how they reach agreements to cooperate with law enforcement to how jurors evaluate their testimony in court. The present study focuses on this last area – juror perceptions of informants who testify. The limited research that exists on this topic has presented troubling conclusions: jurors may not be appropriately responsive to cues that could signal informant unreliability. In particular, jurors may fail to account for and properly weigh evidence that an informant is testifying for an incentive (such as a reduced prison sentence) when reaching a verdict. However, thus far, studies in this area have some limitations in case type, materials used, and statistical power. The objective of the current study is to advance in each of these areas and provide new evidence about the impact of juror perceptions of informant incentives. This study used a novel fact pattern, video stimuli manipulations, and a sample of 886 online participants to test the impact of informant incentives on juror judgments. It featured four conditions that vary the nature and size of the incentive reported by a jailhouse informant (i.e., no incentive, a vague leniency incentive, and small and large sentence reduction incentives), plus a control condition with no informant testimony. The results speak to the conflicted literature on this topic – finding a significant impact of incentive presence on verdicts. Participants who observed an incentivized informant rated him as less credible and were less likely to convict the defendant based on his testimony – compared to participants who viewed an otherwise identical non-incentivized informant. However, participants’ verdicts in this study were not sensitive to changes in the size of an informant’s incentive, showing no significant difference in conviction rates when the incentive was large (10 years off of a 20-year sentence) compared to small (1 year off of a 20-year sentence). This study also included a test of a novel hope-for-leniency condition, which prompted verdict responses most similar to that of the small incentive condition. These results suggest that jurors may be more capable than previously thought at accounting for informant incentives in reaching a verdict. It also suggests that reforms that aim to preserve evidence of jailhouse informant incentives and ensure that such information is able to reach a jury at trial have potential to meaningfully influence verdict outcomes
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On Informing Jurors of Potential Sanctions
With few exceptions, jurors in criminal trials exclusively determine whether the defendant is guilty; they do not determine what the sanction is or even recommend what it should be. However, anecdotal evidence suggests that jurors make assumptions regarding the potential punishment, and that these assumptions inform their verdicts. This is rational behavior according to Decision Theory. Thus, several legal scholars have argued that jurors ought to be informed of the possible punishment that would follow a guilty verdict, in order to disabuse incorrect assumptions and make an informed decision. The present experiments tested: a.) whether jurors do make assumptions about the potential punishment that would follow from a guilty verdict; b.) whether those assumptions influence jurors’ implicit threshold for reasonable doubt; and c.) whether informing jurors of the potential punishment additionally influences their implicit threshold. Experiment 1 manipulated the alleged crime (Grand Theft vs. Manslaughter) holding all other factors constant, and found that mock jurors (n=102, recruited via Amazon Mechanical Turk) had different expectations about the relative punishments but that these expectations did not affect their implicit threshold for reasonable doubt. Experiment 2 manipulated the alleged crime as well as a judicial description of the potential punishment (e.g., term of incarceration of 2-6 vs 7-20 years). Again, mock jurors (n=297) were sensitive to the relative punishments, yet their implicit threshold did not differ on this basis. These findings call into question whether jurors should be informed of the potential punishment if the defendant is convicted
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The Impact of Narrative Consistency on Jurors' Utilization of DNA Evidence
The Story Model of Juror Decision Making states that as jurors are exposed to new pieces of evidence, they continually integrate evidence into a “story” about what happened in the case; this process includes evaluating contradictory testimony and discounting evidence that does not fit within the juror’s narrative about the case. Existing research has neglected to test how forensic DNA evidence is incorporated into jurors’ narratives, especially if the DNA is inconsistent with the non-forensic evidence. The lack of emphasis on forensic evidence should be addressed given the perception of infallibility that surrounds DNA. Study 1 manipulated non-forensic evidence strength and whether there was a DNA match to test how jurors integrated DNA evidence into their narrative interpretation of the case. Results indicated that utilization of forensic testimony depended on the non-forensic evidence strength and reliance on non-forensic evidence depended on whether there was a DNA match. To expand the results from Study 1 and incorporate the possibility of error in DNA testing, Study 2 manipulated whether a DNA match did or did not contain laboratory error rate evidence and the strength of the non-forensic evidence to examine how jurors integrate error rates into their narrative about a case. Results showed that jurors were not sensitive to the laboratory error rates manipulation. Together, these studies indicate that jurors are not sensitive to the possibility of erroneous DNA results, but integrate DNA identifications into their narrative; this suggests that bias might be integrated into their narratives that facilitate false convictions
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Detecting Deception in Children: A Meta-Analysis
Although research consistently reveals that children as young as three can use deception and will take steps to obscure truth, research concerning how well others detect children’s deceptive efforts remains unclear. Yet, adults regularly assess whether children are telling the truth in a variety of contexts, including school, home, and legal settings, particularly in investigations of maltreatment. We conducted a meta-analysis to synthesize extant research concerning adults’ ability to detect deceptive statements produced by children. We included 45 experiments involving 7,893 adult judges and 1,858 children. Overall, adults could accurately discriminate truths/lies at an average rate of 54.3%, which is significantly above chance levels. The average rate at which true statements were correctly classified as honest was higher (59.7%), while the rate at which false statements were classified as dishonest was at chance (49.4%). A small positive correlation emerged between judgment confidence and judgment accuracy. Professionals (e.g., social workers; police officers) slightly outperformed laypersons (e.g., college undergraduates). Finally, exploratory analyses revealed that the child’s age did not affect the rate at which adults could discriminate truths/lies but it was trending in the expected developmental direction (i.e., adults were most accurate when judging younger children)
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Criminal Minds Cannot Be Disabled: Intellectual Disability in Capital Cases
The Supreme Court ruled in Atkins v. Virginia (2002) that intellectually disabled defendants cannot be sentenced to death. However, little is known about how intellectual disability judgments are made by jurors in capital cases. Our experiment addresses this gap by examining the impact of both clinical expert opinions and crime information on jurors’ disability judgments and death sentencing behavior. In a study of 286 venire jurors, we found that expert opinions significantly influenced juror disability decisions and death sentencing – with juror judgments tending to align with expert opinions – and exposure to crime details made jurors significantly more likely to sentence the defendant to death. Our results suggest that to protect the rights of disabled defendants, it may be necessary for courts to have a separate hearing on the issue of intellectual disability specifically – without crime details – to ensure jurors are not unduly influenced
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Disentangling Normative and Informational Influence in Group Decision Making
Although extensive social psychological research has examined conformity for individualized behaviors, no laboratory research has experimentally manipulated conformity in the context of group decisions. Normative conformity is motivated by the desire for social acceptance while informational conformity entails looking to others for correct answers. Using the applied context of a jury deliberation, the present studies aimed to disentangle the relative effects of normative and informational conformity by comparing participants’ votes and ratings of evidence convincingness before and after exposure to a confederate group’s opinions during a poll. Private polls were intended to shield jurors from normative influence, while public polls invited conformity via both normative and informational influence. Results showed disagreement with the group majority during the first poll was a consistently strong predictor of vote switching, but no significant differences emerged in vote switching between public and private deliberation. Changes in beliefs about the strength of the evidence against the defendant partially mediated the effect of a disagreeing majority on vote switching. For participants who initially voted guilty, changes in beliefs drove a greater proportion of conformist vote switching in public deliberations than in private deliberations. This finding suggests that people may weigh public comments in group decisions more heavily or that the pressure to conform in public deliberation may increase susceptibility to belief change. More generally, it also suggests that normative pressure may sometimes fuel informational influence, and that the two constructs may be more linked than previously conceptualized. Implications are discussed for extant research on the intersection between conformity and group decision making and for jury protocol
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Rap Lyrics as Evidence: An Examination of Rap Music, Perceptions of Threat, and Juror Decision Making
In courtrooms across the U.S., defendant-authored rap lyrics are being introduced as incriminating evidence. Prosecutors describe these lyrics as an admission of guilt. Others, however, fear rap lyrics are being used as evidence because of stereotypes about the genre and the artists associated with it, which may affect trial outcomes. Only a handful of studies have empirically examined concerns about this practice, and these studies are methodologically limited and becoming increasingly outdated. My dissertation involves a set of studies that address these limitations and build upon previous research. In Study 1, which consists of three experiments, I examined the impact of genre-specific stereotypes on the evaluation of violent song lyrics by manipulating the musical genre ascribed to the lyrics while holding constant the actual lyrics. Experiment 1, a direct replication of previous research, found that participants deemed identical lyrics more literal, offensive, and in greater need of regulation when they were characterized as rap compared to country. I found in Experiment 2 that this genre effect was not unique to one set of lyrics and in Experiment 3 that it was not influenced by the race of the songwriter. Findings from Study 2, which used a similar design as Study 1, revealed that the songwriter of the lyrics was viewed more negatively across a number of dimensions when the lyrics were categorized as rap rather than country, punk, or heavy metal. Finally, in Study 3, I examined the adjudicative consequences of using rap lyrics as evidence in a criminal trial. In particular, participants evaluated rap lyrics in two contexts, one of which was a trial, and then provided a verdict for the trial. Results revealed that participants who believe a defendant is guilty were more likely to treat rap lyrics as an admission of guilt compared to when the lyrics were not presented in the trial context, however evaluations of the lyrics did not predict verdict. Ultimately, these findings provide insight into the potential consequences of introducing rap lyrics as evidence at trial
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