CHRISTIE, SECTION 137 AND FORENSIC SCIENCE EVIDENCE (AFTER DUPAS v THE QUEEN v AND R v XY ) Y GARY EDMOND,* DAVID HAMER,** ANDREW LIGERTWOOD*** AND MEHERA SAN ROQUE**** I INTRODUCTION This article addresses the implications of Dupas v The Queen 1 and R v XY d 2 Y Y for the handling of expert evidence under s 137 of the Uniform Evidence Law (UEL). 3 Focused on forensic science and medicine evidence, and in anticipation of High Court consideration, we offer an alternative lens through which to approach the current dialogue between the New South Wales and Victorian appellate courts. 4 Whatever their differences, both Dupas and XY are concerned with the obligation of the court to limit the admissibility of evidence that has the potential to mislead or be misused by the trier of fact and thereby undermine rational decision making. This article directs attention to an enhanced role for s 137 in the regulation and, where appropriate, exclusion of incriminating ‘expert’ evidence. 5 In this article we offer an account — influenced by emerging evidence on the weaknesses of the contemporary forensic sciences — of how expert evidence led by prosecutors has the potential to mislead and be misused by the trier of fact (in particular the jury) in ways that cannot be easily or adequately addressed by conventional trial safeguards. These risks are accentuated where opinions are derived from forensic science techniques that have not been formally evaluated, 1 (2012) 218 A Crim R 507 (‘Dupas’). 2 (2013) 84 NSWLR 363 (‘XY’). For a more detailed description, see Michael W R Adams and Christopher K Wareham, ‘Is Judicial Consideration of Credibility and Reliability under Section 137 of the Uniform Evidence Law a Guarantee of Fairness or “Moral Treason”?’(2014) 40 Monash University Law Review 243. 3 The uniform evidence legislation (UEL) now covers all major jurisdictions with the exception of Queensland, South Australia and Western Australia. See Evidence Act 1995 (Cth); Evidence Act 201 1 (ACT); Evidence Act 1995 (NSW); Evidence Act 2004 (Norfolk Island); Evidence (National Uniform Legislation) Act 2011 (NT); Evidence Act 2001 (Tas); Evidence Act 2008 (Vic). 4 It is not our intention to resolve the tensions in these cases, but rather to discuss the decisions in the context of an attempt to reiterate the purpose of s 137 and its common law progenitor R v Christie [1914] AC 545 (‘Christie’), and the particular risks introduced by incriminating expert evidence. 5 ‘Expert’ is placed in quotation marks because in a surprising number of cases we do not know whether the individuals allowed to proffer their incriminating opinions actually possess any relevant expertise. * Professor, Australian Research Council Future Fellow, and Director, Expertise, Evidence & Law Program, School of Law, The University of New South Wales, Sydney 2052, Australia. Email: g.edmond@unsw.edu.au. ** Associate Professor, School of Law, University of Sydney. *** Emeritus Fellow, School of Law, University of Adelaide. **** Senior Lecturer, School of Law, The University of New South Wales.