Simply Unconvincing: The High Court on Probative Value and Reliability in the Uniform Evidence Law

Abstract

Exclusion of evidence when its probative value is exceeded by its risk of creating unfair prejudice has long been a fundamental safeguard against wrongful convictions. In 2016, IMM v The Queen curtailed that safeguard by holding that trial judges should assess probative value on the assumption that the evidence is reliable and credible. The IMM majority placed emphasis on the capacity of the evidence. In doing so, it provided a mysterious qualification: some evidence may lack probative value not because it is unreliable, but because it is ‘simply unconvincing’. The majority illustrated unconvincingness with the example of an unreliable eyewitness identification. Courts and legal scholars criticised the majority’s judgment for its harmful implications and for its apparent incoherence. From a review of almost four years of post-IMM jurisprudence and deeper exploration into one particular case, we find that ‘simply unconvincing’ has accentuated the confusion and inconsistency in Australian evidence jurisprudence.

Keywords: evidence law, IMM v The Queen, probative value, 135, 137, reliability, eyewitness identification, expert evidence

JEL Classification: k14, k10, k30, k40