Unpacking workplace stress and forensic expert decision-making: From theory to practice.

Workplace stress can affect forensic experts' job satisfaction and performance, which holds financial and other implications for forensic service providers. Therefore, it is important to understand and manage workplace stress, but that is not simple or straightforward. This paper explores stress as a human factor that influences forensic expert decision-making. First, we identify and highlight three factors that mitigate decisions under stress conditions: nature of decision, individual differences, and context of decision. Second, we situate workplace stress in forensic science within the Challenge-Hindrance Stressor Framework. We argue that stressors in forensic science workplaces can have a positive or a negative impact, depending on the type, level, and context of stress. Developing an understanding of the stressors, their sources, and their possible impact can help forensic service providers and researchers to implement context-specific interventions to manage stress at work and optimize expert performance.

The low prevalence effect in fingerprint comparison amongst forensic science trainees and novices.

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.

A practical tool for information management in forensic decisions: Using Linear Sequential Unmasking-Expanded (LSU-E) in casework.

Forensic analysts often receive information from a multitude of sources. Empirical work clearly demonstrates that biasing information can affect analysts' decisions, and that the order in which task-relevant information is received impacts human cognition and decision-making. Linear Sequential Unmasking (LSU; Dror et al., 2015) and LSU-Expanded (LSU-E; Dror & Kukucka, 2021) are examples of research-based procedural frameworks to guide laboratories' and analysts' consideration and evaluation of case information. These frameworks identify parameters-such as objectivity, relevance, and biasing power-to prioritize and optimally sequence information for forensic analyses. Moreover, the LSU-E framework can be practically incorporated into any forensic discipline to improve decision quality by increasing the repeatability, reproducibility, and transparency of forensic analysts' decisions, as well as reduce bias. Future implementation of LSU and LSU-E in actual forensic casework can be facilitated by concrete guidance. We present here a practical worksheet designed to bridge the gap between research and practice by facilitating the implementation of LSU-E.

Do laypeople recognize youth as a risk factor for false confession? A test of the 'common sense' hypothesis.

In a survey of confession experts, 94% agreed that youth is a risk factor for false confession, but only 37% felt that jurors understand this. To date, no study has tested the latter by comparing laypeople's perceptions of juvenile and adult suspects. To address this gap, Experiment 1 participants read a lengthy (i.e. interrogation and confession) or abridged (i.e. confession-only) transcript of an ostensibly juvenile or adult suspect's interrogation. Transcript length affected perceived pressure but not guilt judgments. Suspect age had little effect, with 75% of participants misjudging the juvenile as guilty. Experiment 2 then tested how expert testimony affects judgments of juvenile suspects. Participants read a lengthy or abridged interrogation transcript, with or without testimony from a juvenile confession expert. Expert testimony somewhat impacted guilt judgments but did not influence perceptions of the interrogation. Implications for interrogation practices, trial procedure and future research are discussed.

Cognitive bias in forensic pathology decisions.

Forensic pathologists' decisions are critical in police investigations and court proceedings as they determine whether an unnatural death of a young child was an accident or homicide. Does cognitive bias affect forensic pathologists' decision-making? To address this question, we examined all death certificates issued during a 10-year period in the State of Nevada in the United States for children under the age of six. We also conducted an experiment with 133 forensic pathologists in which we tested whether knowledge of irrelevant non-medical information that should have no bearing on forensic pathologists' decisions influenced their manner of death determinations. The dataset of death certificates indicated that forensic pathologists were more likely to rule "homicide" rather than "accident" for deaths of Black children relative to White children. This may arise because the base-rate expectation creates an a priori cognitive bias to rule that Black children died as a result of homicide, which then perpetuates itself. Corroborating this explanation, the experimental data with the 133 forensic pathologists exhibited biased decisions when given identical medical information but different irrelevant non-medical information about the race of the child and who was the caregiver who brought them to the hospital. These findings together demonstrate how extraneous information can result in cognitive bias in forensic pathology decision-making.

Forensic Confirmation Bias: Do Jurors Discount Examiners Who Were Exposed to Task-Irrelevant Information?*, †.

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.

Juror appraisals of forensic evidence: Effects of blind proficiency and cross-examination.

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.