Introduction

18.1 In jury trials, the general rule is that questions of law are determined by the judge and questions of fact are determined by the jury. However, the judge controls the framework within which the fact-finding process occurs: first, in the application of the rules of admissibility (particularly in the exercise of a discretion to exclude evidence); and secondly, in directing the jury as to the legal rules that it must apply to the evidence. The latter task encompasses a responsibility to direct the jury about any legal limits on the use it may make of the evidence^[1] and to give an appropriate warning or caution where there are potential ‘dangers’ involved in acting upon particular evidence.^[2] The trial judge may also make comments about the evidence and, to some extent, express opinions as to what conclusions appear appropriate.^[3]

18.2 The matters about which a warning will be required are usually those with which the court is said to have ‘special experience’ not possessed by members of the jury.^[4] Warnings must therefore be given in terms which convey that they are binding directions of law.^[5] The duty of a trial judge to give appropriate and adequate warnings stems from the overriding duty to ensure a fair trial.^[6] Hence the failure to give an appropriate warning may lead to a miscarriage of justice.^[7] In contrast, a comment is usually given where it is considered that the matters referred to are within the common understanding or experience of the members of the jury, but which they may have overlooked or forgotten.^[8] Comments are not binding on the jury and should be given in terms that make this clear.^[9]

18.3 The uniform Evidence Acts do not contain a comprehensive guide as to what comments, warnings and directions may be permitted or required. However, the Acts expressly provide for the following: comments on the failure of an accused to give evidence or call a witness (s 20); warnings about ‘evidence of a kind that may be unreliable’ (s 165); and warnings in relation to identification evidence (s 116).^[10] Other comments, warnings and directions in relation to evidence are provided for by the common law and other pieces of substantive and procedural legislation.^[11]

18.4 This chapter does not attempt a comprehensive review of comments, warnings and directions to the jury, as this is considered to be beyond the scope of the present Inquiry. The chapter will focus on the warnings expressly provided for in the uniform Evidence Acts,^[12] and those common law warnings which submissions and consultations indicate are areas of significant concern.