Forensics without uniqueness, conclusions without individualization: the new epistemology of forensic identification

Abstract

Among the causes of the current sense that the forensic identification disciplines are ‘under siege’ are conceptual difficulties in these disciplines. Forensic identification disciplines either claim to achieve or strive to achieve conclusions of ‘individualization’, the reduction of the donor pool to a single source. They tend to support such claims by reference to the supposed ‘uniqueness’ of their objects of analysis. Both these notions remain extremely salient among practitioners and courts. And yet, a broad consensus in the forensic literature holds that individualization is unachievable and uniqueness is largely irrelevant to supporting claims of individualization. Focusing on latent print evidence, this article provides a clear articulation of the need to make a clean break from both individualization and uniqueness as forensic concepts. It argues that trace evidence disciplines can live without these concepts, and it explores what defensible conclusions might look like and how they might be supported.