Public Policy, Police Interest: A Re-Evaluation of the Judicial Discretion to Exclude Improperly or Illegally Obtained Evidence
Presser, Bram, Melbourne University Law Review
[This research note evaluates the public policy head of the discretion to exclude illegally or improperly obtained evidence in light of the recent changes contained in the Evidence Act 1995 (Cth) and (NSW) and the High Court's decision in R v Swaffield; Pavic v The Queen. It examines 39 cases, decided both before and after the changes, and concludes that, while the discretion remains largely impotent, the changes do give some cause for hope that the discretion may yet turn out to be an effective police accountability mechanism, albeit in limited circumstances.]
Over the past three decades, numerous government inquiries and academic studies have raised serious concerns about the manner in which the police investigate crime and, perhaps more significantly, the efficacy of the investigative process itself. In particular, these studies have identified process corruption, (1) corruption for personal gain, (2) discrimination, (3) the use of excessive force (4) and procedural incompetence (5) as impeding ethical and effective criminal investigations.
A complex web of accountability mechanisms has evolved in an attempt to deal with these problems. Internal mechanisms, civil actions, criminal prosecutions, civilian review bodies, and independent commissions of inquiry have all played an important part in improving investigative and ethical standards. Yet none of these mechanisms is so directly geared to the minutiae of the investigative process as the judicial discretion to exclude evidence obtained through illegal or improper means. Indeed, it could be argued that the exclusion of evidence may be -- at least in theory -- the most effective of the existing mechanisms in that it is part of the criminal justice system itself, and targets the main purpose of criminal investigations, namely successful prosecutions.
Previous analyses of the discretion have concluded that it is not effective as an accountability mechanism. For example, Sallman and Willis assert that police failure to conform to laws and guidelines has `often been tolerated by courts who have seen the conviction of persons they perceived to be clearly guilty [to be] of more importance than the control of police practices'. (6) Similarly, the Wood Report found that process corruption, even though unlawful, `accords with long standing practice [and] only infrequently leads to the exclusion of evidence'. (7) However, recent changes to the law of evidence, as contained in the Evidence Act 1995 (Cth) and (NSW) (`uniform evidence legislation') and R v Swaffield; Pavic v The Queen (8) necessitate a re-evaluation of the discretion. Both of these developments sought to clarify the operational contours of the discretion and to allow for its coherent invocation by judges. Yet it remains to be seen whether they were merely cosmetic changes or whether the discretion might finally take its place as an effective and important police accountability mechanism.
II THE EXCLUSIONARY PHOENIX: POLICE MISCONDUCT, FAIRNESS AND PUBLIC POLICY
The discretion to exclude illegally or improperly obtained evidence is but one part of a large body of rules regulating the admissibility of evidence. Police misconduct undoubtedly affects the operation of other rules but it is only a peripheral consideration in the admissibility equation pertaining to those rules. Indeed, most of those rules are independently defendant- and condition-focused, designed to ensure that only relevant and reliable evidence is admitted. Where police conduct renders evidence unreliable, it will lead to exclusion. But it is not the nature of the misconduct that is at issue. Rather, it is the effect the conduct had on the defendant -- whether the conditions created were such as to cast doubt upon the reliability of the evidence. Furthermore, many other factors completely unrelated to the police might also render evidence inadmissible. The discretion to exclude improperly or illegally obtained evidence, on the other hand, is wholly concerned with the conduct of the police and may, at times, result in the exclusion of otherwise reliable evidence. …