Decision-making at the crime scene: A scoping literature review on the cognitive aspects of crime scene examination and the influence of rapid testing

Rapid tests will likely become increasingly available to crime scene investigators and have the potential to fundamentally change how decisions are made during the examination of the crime scene. By speeding up the analysis of traces, preliminary results from on-site rapid testing can already be used to support decision-making at the crime scene and may ultimately transform how crime scenes are examined. However, crime scene investigators' decision-making remains influenced by cognitive factors that also affect current examination practices. Given the lack of practical guidance on decision-making in guidelines and forensic science handbooks, it is essential to understand how crime scene investigators make decisions in practice. In this scoping literature review (N = 32), we examine how crime scene investigators search for, interpret, collect, and analyse traces, and how the introduction of rapid tests may influence these decision-making processes. The review reveals that guidelines and handbooks have paid little attention to cognitive factors that may shape investigators’ observations and decisions. Empirical studies, however, show that cognitive factors play an important role in the decision-making at the crime scene. Understanding these influences is becoming increasingly important as rapid testing may affect early decision-making and, in turn, may iteratively shape the course of the investigation. Further research is therefore needed to better understand how rapid testing may influence decision-making at the crime scene.