5. Conclusion
We have presented here a methodology for constructing BNs for the biology component of forensic evaluations when activity level propositions are being considered by the Court. The method is flexible enough that many cases with different circumstances can be evaluated in this way, but standard enough that an analyst looking at the BN (or starting to think about how to construct a BN for a case) should be able to progress quite quickly through the architecture and understand the flow of information. The seven proposed steps are relatively simple, although there can be much work that underlies each step, and we have demonstrated their use in a worked example that is based on a real case example. More generally, techniques for sound BN structure building extend to considerations of combining evidence, a topic that we consider inevitable for any attempt to derive more fine-grained analyses [42,43].
We emphasize that our template approach does not prescribe any pre-built network structures, it only recommends steps for structuring the thinking process. Indeed, we insist on the importance of the expert being in full control of the construction and use of the BN at any point, as BNs should be constructed on a case per case basis to ensure coherence and a faithful capturing of the case features. BNs are expert support systems, not intended to replace experts but to assist them in their critical thinking.
