Systematic review on trace processing and forensic science contributions. Part II: Measuring the contribution of...

Measuring the value of forensic science is crucial for helping law enforcement agencies allocate resources more effectively, ultimately enhancing policing outcomes. However, this assessment is neither straightforward nor uniform. Through the results of a systematic literature review of studies examining the contribution of forensic science, this study investigates two key questions. A first challenge lies in defining the specific contributions of forensic science, which are closely tied to the definition of forensic science itself, its utility dimensions, and its roles within the criminal justice process. Secondly, these roles vary across cases and contexts, necessitating the use of diverse evaluation metrics. Quantitative metrics, such as the number of traces collected or analysed, lead times, and case clearance rates, provide measurable outcomes, while qualitative measures, including decision-making factors, reasons for trace analysis, and the informational impact on investigations, capture subtler contributions. The findings reveal that forensic science's perceived value is highly dependent on roles given to or expected by forensic science (operational, strategic or symbolic), impacting factors (personnel, contextual, conceptual and structural) and the metrics and frameworks applied. These results highlight the importance of adopting a holistic and context-sensitive approach to evaluation. By addressing these challenges, this study provides valuable insights for policymakers, practitioners, and researchers aiming to optimise the integration of forensic science into the criminal justice process.