Communicating forensic evidence: Is it appropriate to report posterior beliefs when DNA evidence is obtained through a database search?

• NCJ Number: 253961
• Journal: Law Probability & Risk Volume: 1 Issue: 18 Dated: 2019 Pages: 25-34
• Author(s): C. Neumann; M. Ausdemore
• Date Published: 2019
• Length: 10 pages
• Grant Number(s): 2014-IJ-CX-K088; 2018-R2-CX-0010
• Agencies: NIJ-Sponsored
• Award: Foundational Research into the Quantification of the Value of Forensic Evidence for Complex Evidential Forms arising from Impression and Pattern Evidence; Development of a probabilistic multiclass model selection algorithm for high-dimension and complex data encountered in forensic pattern and trace evidence.

Annotation

This article discusses the lack a uniform system and common vocabulary for presenting conclusions about the sources of the traces or the weight of the evidence associated with these traces in forensic science.

Abstract

Forensic scientists lack a uniform system and common vocabulary for presenting conclusions about the sources of the traces or the weight of the evidence associated with these traces. Practices vary both across fields and sometimes within them. Several modes of presentation coexist, such as categorical conclusions (e.g. 'the trace has been identified as coming from Mr. X'), or less definitive but easily misunderstood observations (such as 'the trace is consistent with coming from Mr. X' or 'the trace matches Mr. X'). In some fields, practitioners qualify their conclusions about the identity of sources with verbal probabilities (such as 'there is a strong probability than Mr. X left the trace').