Abstract

co-authors J de Koeijer, J de Zoete and B Kokshoorn 

The Netherlands Forensic Institute is currently exploring the use of Bayesian networks in their forensic casework. We identified a number of different ways that networks can be used, e.g., as a probability calculator, as an exploratory tool for complex problems and as a reasoning tool. In this presentation we focus on the latter and discuss a recent case in which Bayesian networks were used in this way. The case concerned a series of six different robberies in which several DNA matches with a suspect were found on “movable objects” in each case. We were asked to assess the evidential value of the combined DNA evidence. Bayesian networks proved to be very valuable to assist in our reasoning and in busting a few important DNA myths that are common in the legal domain. We chose not to report the networks themselves but only the reasoning, and explain why.