Chapter 6
The fact-finder in sexual violence cases

The function of the jury in a criminal trial

6.3The function of the jury in a criminal trial is to determine the relevant facts of the case and to apply the law to reach a verdict of guilty or not guilty – to act as the “fact-finder”. When fulfilling this function it is expected that the “diversity of knowledge, perspectives and personal experiences of a representative jury enhances the collective competency of the jury as fact-finder”.431 In addition, juries:432

6.4A jury is not an expert in the law or in the conduct being tried before the court. Their function is to make a determination, from a layperson’s perspective, on whether or not the conduct in question has been established to the criminal standard of proof. Juries are not to apply moral judgments to the people involved, but jurors are to bring their collective life experience and common sense to bear on the facts of the case before them.

6.5The juror decision-making model is a core feature of common law (that is, English-based) criminal jurisdictions, which are adversarial in nature and rely on a “battle” to get to the truth between defence and prosecution, conducted in front of a jury. This is not the case in civil law European jurisdictions, which apply an inquisitorial model of decision-making to determine whether a criminal offence has occurred.433
6.6Criticisms have been levelled at the jury-based model of fact-finding. These include that many juries are not truly representative of society, that jurors may allow themselves to be improperly influenced by things that are not relevant to the trial and that some cases are too detailed or specialised for lay jurors.434 The Criminal Procedure Act 2011 (CPA 2011) enables trial by judge-alone in cases likely to be long and complex (except where the offence has a maximum penalty of imprisonment for life or 14 years or more).435
6.7Despite any criticisms, trial by jury remains a core feature of the New Zealand criminal justice system. It has been described as “central in New Zealand law”.436
431Law Commission Juries in Criminal Trials Part One: A discussion paper (NZLC PP32, 1998) at [24].
432Law Commission Juries in Criminal Trials (NZLC R69, 2001) and Law Commission, above n 431.
433See Law Commission Alternative Pre-trial and Trial Processes: Possible Reforms (NZLC IP30, 2012), appendix 1.
434See Law Commission Juries in Criminal Trials, above n 432. Issues relating to jurors accessing and sharing extraneous material with other jurors are also covered in Law Commission Contempt in Modern New Zealand (NZLC IP36, 2014) at ch 5.
435Criminal Procedure Act 2011, s 102.
436Siemer v Siemer [2004] 1 AC 1118, 1131-1132 (HL).