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The low prevalence effect is a phenomenon whereby target prevalence affects performance in visual search (e.g., baggage screening) and comparison (e.g., fingerprint examination) tasks, such that people more often fail to detect infrequent target stimuli. For example, when exposed to higher base-rates of 'matching' (i.e., from the same person) than 'non-matching' (i.e., from different people) fingerprint pairs, people more often misjudge 'non-matching' pairs as 'matches'-an error that can falsely implicate an innocent person for a crime they did not commit. In this paper, we investigated whether forensic science training may mitigate the low prevalence effect in fingerprint comparison. Forensic science trainees (n = 111) and untrained novices (n = 114) judged 100 fingerprint pairs as 'matches' or 'non-matches' where the matching pair occurrence was either high (90%) or equal (50%). Some participants were also asked to use a novel feature-comparison strategy as a potential attenuation technique for the low prevalence effect. Regardless of strategy, both trainees and novices were susceptible to the effect, such that they more often misjudged non-matching pairs as matches when non-matches were rare. These results support the robust nature of the low prevalence effect in visual comparison and have important applied implications for forensic decision-making in the criminal justice system., Competing Interests: The authors have declared that no competing interests exist.

Knowledge of task-irrelevant information influences judgments of forensic science evidence and thereby undermines their probative value (i.e., forensic confirmation bias). The current studies tested whether laypeople discount the opinion of a forensic examiner who had a priori knowledge of biasing information (i.e., a defendant's confession) that could have influenced his opinion. In three experiments, laypeople (N = 765) read and evaluated a trial summary which, for some, included testimony from a forensic examiner who was either unaware or aware of the defendant's confession, and either denied or admitted that it could have impacted his opinion. When the examiner admitted that the confession could have influenced his opinion, laypeople generally discounted his testimony, as evidenced by their verdicts and other ratings. However, when the examiner denied being vulnerable to bias, laypeople tended to believe him-and they weighted his testimony as strongly as that of the confession-unaware examiner. In short, laypeople generally failed to recognize the superiority of forensic science judgments made by context-blind examiners, and they instead trusted examiners who claimed to be impervious to bias. As such, our findings highlight the value of implementing context management procedures in forensic laboratories so as not to mislead fact-finders., (© 2020 American Academy of Forensic Sciences.)

Forensic testimony plays a crucial role in many criminal cases, with requests to crime laboratories steadily increasing. As part of efforts to improve the reliability of forensic evidence, scientific and policy groups increasingly recommend routine and blind proficiency tests of practitioners. What is not known is how doing so affects how lay jurors assess testimony by forensic practitioners in court. In Study 1, we recruited 1398 lay participants, recruited online using Qualtrics to create a sample representative of the U.S. population with respect to age, gender, income, race/ethnicity, and geographic region. Each read a mock criminal trial transcript in which a forensic examiner presented the central evidence. The low-proficiency forensic examiner elicited a lower conviction rate and less favorable impressions than the control, an examiner for which no proficiency information was disclosed. However, the high-proficiency examiner did not correspondingly elicit a higher conviction rate or more favorable impressions than the control. In Study 2, 1420 participants, similarly recruited using Qualtrics, received the same testimony, but for some conditions the examiner was cross-examined by a defense attorney. We find cross-examination significantly reduced guilty votes and examiner ratings for low-proficiency examiners. These results suggest that disclosing results of blind proficiency testing can inform jury decision-making, and further, that defense lawyering can make proficiency information particularly salient at a criminal trial., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Knowledge of task‐irrelevant information influences judgments of forensic science evidence and thereby undermines their probative value (i.e., forensic confirmation bias). The current studies tested whether laypeople discount the opinion of a forensic examiner who had a priori knowledge of biasing information (i.e., a defendant's confession) that could have influenced his opinion. In three experiments, laypeople (N = 765) read and evaluated a trial summary which, for some, included testimony from a forensic examiner who was either unaware or aware of the defendant's confession, and either denied or admitted that it could have impacted his opinion. When the examiner admitted that the confession could have influenced his opinion, laypeople generally discounted his testimony, as evidenced by their verdicts and other ratings. However, when the examiner denied being vulnerable to bias, laypeople tended to believe him—and they weighted his testimony as strongly as that of the confession‐unaware examiner. In short, laypeople generally failed to recognize the superiority of forensic science judgments made by context‐blind examiners, and they instead trusted examiners who claimed to be impervious to bias. As such, our findings highlight the value of implementing context management procedures in forensic laboratories so as not to mislead fact‐finders. [ABSTRACT FROM AUTHOR]

Knowledge of task‐irrelevant information influences judgments of forensic science evidence and thereby undermines their probative value (i.e., forensic confirmation bias). The current studies tested whether laypeople discount the opinion of a forensic examiner who had a priori knowledge of biasing information (i.e., a defendant's confession) that could have influenced his opinion. In three experiments, laypeople (N = 765) read and evaluated a trial summary which, for some, included testimony from a forensic examiner who was either unaware or aware of the defendant's confession, and either denied or admitted that it could have impacted his opinion. When the examiner admitted that the confession could have influenced his opinion, laypeople generally discounted his testimony, as evidenced by their verdicts and other ratings. However, when the examiner denied being vulnerable to bias, laypeople tended to believe him—and they weighted his testimony as strongly as that of the confession‐unaware examiner. In short, laypeople generally failed to recognize the superiority of forensic science judgments made by context‐blind examiners, and they instead trusted examiners who claimed to be impervious to bias. As such, our findings highlight the value of implementing context management procedures in forensic laboratories so as not to mislead fact‐finders. [ABSTRACT FROM AUTHOR]

Abstract: Psychology has made a tremendous contribution to law by showing the malleability of eyewitness perception and memory, and developing best practices for obtaining eyewitness identifications. We suggest that even expert scientific witnesses, which the court heavily relies on as objective and impartial, are also susceptible to bias from various psychological influences. For example, forensic examiners’ interactions with detectives and exposure to information about the case can bias their judgments. We discuss the ten commentaries on these issues across a range of forensic science domains, and affirm what reforms are needed. [Copyright &y& Elsevier]

Abstract: As illustrated by the mistaken, high-profile fingerprint identification of Brandon Mayfield in the Madrid Bomber case, and consistent with a recent critique by the National Academy of Sciences (2009), it is clear that the forensic sciences are subject to contextual bias and fraught with error. In this article, we describe classic psychological research on primacy, expectancy effects, and observer effects, all of which indicate that context can taint people''s perceptions, judgments, and behaviors. Then we describe recent studies indicating that confessions and other types of information can set into motion forensic confirmation biases that corrupt lay witness perceptions and memories as well as the judgments of experts in various domains of forensic science. Finally, we propose best practices that would reduce bias in the forensic laboratory as well as its influence in the courts. [Copyright &y& Elsevier]

Forensic science errors are not always apparent because the ground truth in criminal cases is not known. The issue of bias in the forensic sciences is further exacerbated because of the following: The adversarial legal system tests the credibility of forensic scientists, and an acknowledgment of bias may be used in court in an attempt to undermine an expert's credibility. The public and the courts have generally accepted forensic science. [Extracted from the article]

Rather than debating the issues of potential bias in forensic pathology decisions and what can be done about it, three of the original authors (Peterson, Gill, and Oliver) decided to engage in a litany of baseless allegations and I ad hominem i attacks. Indeed, the National Association of Medical Examiners (NAME) has filed formal complaints with such allegations against the lead author, which were independently investigated and dismissed. Not only did our paper undergo a rigorous peer review before publication, but it has now also undergone a number of additional thorough and independent investigations in response to formal complaints made by NAME - and in each case, the investigations reaffirmed the validity of our study and found no merit in the complaints. [Extracted from the article]

The article focuses on a study conducted on the impact of contextual bias on forensic identification. There are two sources of contextual bias: exposure to case information, and interaction with investigators. The study included a sample of 885 criminal cases in which law enforcement had taken the help of examiners from a fingerprint laboratory. The researchers concluded that the contextual factors had negligible biasing effect on examiners' identification decisions.