Formulation of propositions for forensic handwriting examinations

Abstract

AbstractThe forensic examiner's role is to assist the court by explaining the significance of their findings within the context of the case. In “evaluative” reporting this is achieved by considering the probability of observing the evidence given at least two competing propositions. This article outlines the requirements of propositions within an evaluative framework, common sets of propositions used in handwriting examinations and their associated basic expectations. As the forensic handwriting examiner may be asked to undertake different types of comparisons depending on the material available and the case circumstances, it is critical that examiners carefully consider the most appropriate propositions against which the findings are to be evaluated. Further, as the propositions are derived from case information, and may require assumptions to be drawn, the necessary disclosure within reports is discussed. Although the examples given are specific to handwriting examinations, the concepts discussed in this article are applicable to other forensic disciplines utilizing an evaluative approach to evidence interpretation.This article is categorized under: Forensic Chemistry and Trace Evidence > Presentation and Evaluation of Forensic Science Output Jurisprudence and Regulatory Oversight > Expert Evidence and Narrative