"Blood, Bucks and Bias": Reliability and biasability of crime scene investigators' selection and prioritization of blood traces

Signs of how the Sydney Declaration article is received in the forensic science literature

The Sydney Declaration is an initiative led by an informal group of forensic scientists with diverse backgrounds. It offers a vision of forensic science based on the trace, as a vestige of a past event related to security or a possible law violation. An article published in Forensic Science International (FSI) introduces to this view [1]. Our investigation delves into how the forensic science literature has received this article (the SD article), nearly two years after its publication. One of the main challenges of this exploratory study was to define the appropriate scope of forensic scientific literature, within which the SD article must be located. In general, the publishing domain is quickly evolving, with many competing players, while still being structured around standard academic disciplines. The forensic literature, meanwhile, is scattered and poorly connected. This reflects the fragmentation of practice and research in forensic science, and the difficulty of situating a scientific activity in such a way as to bring out its forensic substance. Nonetheless, the SD article fills a gap. By deciphering the critical concept of trace, it highlights how pivotal forensic science is in addressing societal challenges. Scholarly literature expresses clear quantitative interest in the SD article. It has received significant qualitative citations on multiple levels and dimensions, in a highly relevant manner and in accordance with its aim of providing a forensic foundation for various debates that have been conducted separately, notably over the last fifteen years.

Bloodstain classification methods: A critical review and a look to the future

Classifying bloodstains is an essential part of Bloodstain Pattern Analysis. Various experts have developed methods. Each method considers the same basic bloodstain pattern types. These use either terminology based on the observable characteristics or the mechanistic cause of the bloodstain patterns as part of the classification process. This review paper considers ten classification methods from fourteen sources, which are used to classify bloodstain patterns. There are fundamental differences in how the patterns are classified, how differentiated the classification is, and whether the classification process uses clear, unambiguous criteria, and is susceptible to contextual bias. Experts have also reported issues with classifying bloodstains that have indistinguishable features. These differences expose key limitations with current classification methods: mechanistic terminology is too heavily relied on, and the classification process is susceptible to contextual bias. The development of an unambiguous classification method, based on directly observable characteristics within bloodstain patterns is recommended for future work.

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.

CSI-CSI: Comparing several investigative approaches toward crime scene improvement

Crime scene investigations are highly complex environments that require the CSI to engage in complex decision-making. CSIs must rely on personal experience, context information, and scientific knowledge about the fundamental principles of forensic science to both find and correctly interpret ambiguous traces and accurately reconstruct a scene. Differences in CSI decision making can arise in multiple stages of a crime scene investigation. Given its crucial role in forensic investigation, CSI decision-making must be further studied to understand how differences may arise during the stages of a crime scene investigation. The following exploratory research project is a first step at comparing how crime scene investigations of violent robberies are conducted between 25 crime scene investigators from nine countries across the world. Through a mock crime scene and semi-structured interview, we observed that CSIs have adopted a variety of investigation approaches. The results show that CSIs have different working strategies and make different decisions when it comes to the construction of relevant hypotheses, their search strategy, and the collection of traces. These different decisions may, amongst other factors, be due to the use of prior information, a CSI's knowledge and experience, and the perceived goal of their investigation. We suggest the development of more practical guidelines to aid CSIs through a hypothetico-deductive reasoning process, where (a) CSIs are supported in the correct use of contextual information, (b) outside knowledge and expertise are integrated into this process, and (c) CSIs are guided in the evaluation of the utility of their traces.

The most consistent finding in forensic science is inconsistency

The most consistent finding in many forensic science domains is inconsistency (i.e., lack of reliability, reproducibility, repeatability, and replicability). The lack of consistency is a major problem, both from a scientific and a criminal justice point of view. Examining forensic conclusion data, from across many forensic domains, highlights the underlying cognitive issues and offers a better understanding of the issues and challenges. Such insights enable the development of ways to minimize these inconsistencies and move forward. The aim is to highlight the problem, so that it can be minimized and the reliability of forensic science evidence can be improved.

The role of alternative hypotheses in reducing bias in forensic medical experts' decision making

Medical opinions are often essential evidence in criminal cases but relatively little is known about the factors that impact forensic doctors' decision making. This research examines the role and impact of having an alternative hypothesis while forming a medical opinion. A scenario-based experiment with forensic doctors (n = 20) was conducted. In two out of three scenarios, the existence of alternative hypotheses impacted the actual opinions reached, the confidence in the judgments and the perceived consistency with the plaintiff hypothesis. Investigative and legal actors should be aware of the possibility of biases and importance of having alternative hypotheses when requesting and evaluating medical opinions.