A probabilistic analysis of cross‐examination using Bayesian networks. Issue 1 (3rd October 2021) - Di Bello, Marcello
Abstract: The legal scholar Henry Wigmore asserted that cross‐examination is 'the greatest legal engine ever invented for the discovery of truth.' Was Wigmore right? Instead of addressing this question upfront, this paper offers a conceptual ground clearing. It is difficult to say whether Wigmore was right or wrong without becoming clear about what we mean by cross‐examination; how it operates at trial; what it is intended to accomplish. Despite the growing importance of legal epistemology, there is virtually no philosophical work that discusses cross‐examination, its scope and function at trial. This paper makes a first attempt at clearing the ground by articulating an analysis of cross‐examination using probability theory and Bayesian networks. This analysis relies on the distinction between undercutting and rebutting evidence. A preliminary assessment of the truth‐seeking function of cross‐examination is offered at the end of the paper.