Expert Evidence of Drug Traces: Relevance, Reliability and the Right to Silence

Abstract

This article examines the U.K. case law on expert evidence of drug traces. It suggests that evidence of questionable relevance is being adduced by the prosecution and that unsuccessful challenges to its reliability have the effect of inflating its probative value. The article reveals troubling synergies between adverse inferences from an accused’s "failure to account" and the adduction of arguably irrelevant scientific evidence. It provides an exposition of the legislative background to s.36 of the Criminal Justice and Public Order Act 1994 and suggests the provision fails to comply with art.6 of the European Convention on Human Rights.

Keywords: Admissibility, Banknotes, Drugs, Expert evidence, Forensic evidence, Right to fair trial, right to silence