Chapter 3
Criminal proceedings


3.1The starting position in criminal law is that relevant material in the possession of the prosecution must be disclosed to the defence prior to the trial, and that, at trial, the defendant is entitled to examine all evidence put before the court.92 This includes information gathered by the prosecution that undermines their case, such as inconsistent witness statements. Disclosure is a vital protection for the accused, allowing them to answer the case being brought and providing scope to question the prosecution’s evidence and challenge their version of events. This is the context for the robust obligations now given statutory grounding in the Criminal Disclosure Act 2008, the Evidence Act 2006, and through the New Zealand Bill of Rights Act 1990 (NZBORA).

3.2However, disclosure obligations have limits. The common law has long recognised the importance of protecting other interests, such as national security or the continued use of sensitive Police investigative methods.93 These exceptions are now contained in statute.94 Where one of the statutory grounds is met, information can be withheld or released in a modified manner (such as through anonymous witnesses giving evidence behind a screen where they may be at risk if their identities are divulged).

3.3An important part of the background to this discussion is the need to ensure that our judicial system has the necessary tools to manage the trial of someone accused of a terrorist activities, in which national security information forms a key part of the evidence (for example, linking the individuals accused of a terrorist act in New Zealand to overseas terrorist entities). While this review is not focused exclusively on such cases, it provides an opportunity to examine current mechanisms for protecting security evidence if a case of this sort was ever to occur in New Zealand. As will be discussed further below, the Criminal Disclosure Act 2008, the Criminal Procedure Act 2011 and the Evidence Act 2006 provide grounds for withholding evidence that raises national security risks. This chapter will consider whether there is a need for additional mechanisms to protect national security information in criminal proceedings, taking account of the fundamental importance of ensuring a fair trial while also giving law enforcement agencies the necessary tools to protect public safety through investigating and prosecuting offences.

92Criminal Disclosure Act 2008, s 13.
93 Exceptions are also available when important private interests arise, for example, the safety of witnesses.
94 The Criminal Disclosure Act 2008, while providing a comprehensive disclosure process, does not affirm its own status as a code, leaving the role of pre-existing common law rules unclear. The Evidence Act 2006 provides in s 10 that its provisions may be interpreted in light of the common law, so far as the common law is consistent with its principles. In practice, the withholding provisions of the Criminal Disclosure Act 2008 and the Evidence Act 2006 cover the same sorts of situations that would have previously given rise to a claim for common law public interest immunity. It is therefore questionable whether there is an ongoing role for this immunity in criminal proceedings.