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Practical Guide for the Formulation of Propositions in the Bayesian Approach to DNA Evidence Interpretation in an Adversarial Environment

NCJ Number
Date Published
January 2016
10 pages
This note explores the issue of proposition setting in an adversarial environment by a series of examples.
The interpretation of complex DNA profiles is facilitated by a Bayesian approach. This approach requires the development of a pair of propositions, one aligned to the prosecution case and one to the defense case. A set of guidelines generalize how to formulate propositions when there is a single person of interest and when there are multiple individuals of interest. Additional explanations cover how to handle multiple defense propositions, relatives, and the transition from sub-source level to activity-level propositions. The propositions depend on case information and the allegations of each of the parties. The prosecution proposition is usually known. The authors suggest that a sensible proposition is selected for the defense that is consistent with their stance, if available, and consistent with a realistic defense if their position is not known. (Publisher abstract modified)

Date Published: January 1, 2016