The Use of Structured Argumentation to Support Conclusions: A Video Authentication Case Study

Digital forensics can narrow key issues pending before a criminal or civil tribunal, resulting in a plea/settlement or a judicially economical trial. To support this, measures facilitating effective discourse between all parties regarding evidential matters may have value to judicial processes, where this session introduces the concept of Structured Argumentation (SA) for this purpose. The use of SA, applied to digital forensics investigations, was proposed and illustrated by Franqueira and Horsman (2020). It allows elaboration of investigative hypotheses, exposing not only how different (digital and/or non-digital) evidence logically fit together, but also the processes followed and conclusions reached, avoiding needless delay when arriving at a plea/disposition in a matter and/or narrowing the issues at a subsequent trial/proceeding. This session will be organised into 3 parts. First, the SA scheme (i.e., claim, ground, warrant, backing and rebuttal) and its dynamics will be described. Second, the results of an evaluation of SA applied to an anonymised video authentication case, from the field, will be presented. Finally, lessons learned and discussion points in relation to the use of SA, in theory and practice, will be elaborated.