The legal structure of propensity evidence

Abstract

The law excluding and admitting evidence of defendants’ other misconduct has long been regarded as overly complex across the common law world. Various reforms have been tried through case law and legislation but without bringing noticeable improvement. In this paper I have sought to identify and understand the sources of complexity through structural analysis. The article provides a close examination of different forms of the exclusionary rule and admissibility tests, the laws’ policy goals, the regulated inferences and the relationship between these various things. The analysis provides neither a neat picture of the law nor a recipe for simplification. Instead it offers a greater understanding of the forces operating on the law, the various forms the law may take and their functionality. Propensity evidence occupies complex heterogeneous terrain, but landmarks, signposts and pathways for reform can be discerned.