Probabilistic analysis in legal factfinding

Abstract

This paper presents and analyzes four actual court cases where an explicit probability model was used as evidence or to quantify the impact of some evidence in the courtroom. Through these cases, an attempt is made to understand some of the possibilities and risks attendant upon quantitative probabilistic analysis in legal factfinding. Although we cannot hope to model the process of forming a judicial belief in its entirely, those facets of factfinding where quantitative estimates are typically made implicitly and intuitively could benefit from the aid provided by tools such as mathematical probability theory and statistics.