Analysis of complex patterns of evidence in legal cases: Wigmore charts vs. Bayesian networks
Valentina Leucari · 2005
Typical features of the evidence arising from legal cases are its complex structure and ambiguity. Therefore, marshalling and evaluating evidence are two fundamental issues in forensic science, both for constructing arguments about questions of fact and for taking final decisions. The chart method for analysing evidence introduced by Wigmore is a technique which allows to organise and describe the available evidence, and to construct reasoning processes through sequential steps. Bayesian networks are a general statistical tool which can be applied in the legal context to model relationships between dierent sources of evidence, weigh the available evidence, and draw statistical inferences from it. Wigmore charts and Bayesian networks are clearly dierent in nature, but they are both an attempt to a rigorous and formal approach to the analysis of evidence. We illustrate and compare such techniques applied to a fictitious burglary example.