Opening the DNA black box: Demythologizing forensic genetics

Abstract

Social impact is intrinsic to any applied branch of genetics. Since the goal of forensic genetics is to provide expertise in legal disputes, the expert should make her-or himself understood. The urgent need for measures to deepen the communication between experts and non-experts requires debunking of some myths surrounding forensic genetics, and to (re)center the discussion on the solid ground of formal genetics. Classical forensic sciences rely on the assumption of discernible uniqueness, while forensic genetics deals with types of observations. It computes expected frequency values for the observations using empirical estimates within a theoretical framework, allowing the evaluation of the probabilities of the same observation under alternative, mutually exclusive and exhaustive hypotheses. Consequently, the interpretation of DNA evidence entails fewer risks of error than classical forensic evidence. However, clear regulations and a total separation between the institutions performing criminal investigation and those acting as expert witnesses are required. © 2012 Copyright Taylor and Francis Group, LLC.