5. The apparent artificiality of insisting on applying the rule against duplicity in its full rigour has been highlighted by actual and theoretical instances that have arisen, or been contemplated, where criminal acts occurred in very close proximity to each other. If, for example, criminal acts occurred within a few minutes of time and in close physical proximity, could they be regarded as components of the one activity, so as to be susceptible to treatment as a single count? If the events were seen as part of the one transaction or criminal enterprise this approach has been held to be permissible in England. If a precise understanding of the charge laid, although evidenced by multiple acts, is that it represents a single crime, then a single count is permissible. Many of the apparently conflicting judicial opinions, so criticised by the commentators, represent nothing more than attempts by judges to characterise multiple acts upon which the prosecution relied and to decide whether or not they could be fairly viewed as the one transaction or criminal enterprise so as to escape an attack on the ground of alleged duplicity. The usual explanation given for adopting this approach is that, only by doing so, would the judges be able to avoid reducing the law to technical absurdity.
6. Particular problems arose for the application of the duplicity rule in the case of offences which, of their definition, were constituted by continuous activity. Such offences as keeping a brothel, required proof of particular acts at different times. Similarly, conduct which need not, but in some circumstances might, be constituted by activity over time could quite properly be charged in a single count. Instances where this qualification to the rule against duplicity has been upheld include cases involving charges of harassment and trafficking in drugs. Obviously, nice questions arise as to whether individual acts of supply of prohibited drugs create the same, or substantially the same, offence so as to sustain a single count and to resist an allegation of duplicity. Various verbal formulae have been offered as a suggested test for whether the criminal acts are sufficiently close in time and space as to 'fairly and properly be identified as part of the same criminal enterprise or the one criminal activity'. These valiant attempts by judges have been criticised as 'glib'. Judges themselves have acknowledged that judicial views in particular cases are not always easy to reconcile. Ultimately, what is presented is a question of fact and degree for decision in each case_._ Various indicia are proposed to sustain a single count against the charge of duplicity, notwithstanding that it may permit evidence to be adduced of events which, taken individually, could constitute separate offences. The indicia include: (a) the connection of the events in point of time; (b) the similarity of the acts; (c) the physical proximity of the place where the events happened; and (d) the intention of the accused throughout the conduct. Perhaps an indication of the considerable difficulty of the task to be found in is the fact that, in many of the leading cases, there is (as in this case) a division of judicial opinion. For instance, Latham CJ dissented in Johnson v Miller; Kitto J dissented in Montgomery v Stewart; and Brennan J (as he then was) dissented in S v The Queen.
7. Because of the foregoing, it must be accepted as correct that 'the courts have never managed to produce a technical verbal formula of precise application which constitutes an easy guide ... as to whether the common law rule [against duplicity] has been infringed'. A choice of legal principle or policy is therefore presented in this appeal which this Court should resolve. Not a great deal of help is given to decisions in a particular case by saying that the test is to look to 'the gist of the offence'. Nor is much help afforded by saying that the test is whether multiple acts can 'fairly and properly' be identified as part of the same criminal enterprise or activity. With respect, it is not very useful to say that it is 'desirable' or 'preferable', where separate offences are arguably shown, that the prosecution should formulate separate charges. Unless courts are prepared to support such homilies with sanctions in the case of breach they are unlikely to much influence day to day prosecution practice. Not a great deal of help to the primary decision-maker is given by suggesting that the test is whether the charge, as formulated, has the potential to confuse or embarrass the accused. Clearly, a great deal depends on the nature of the offence. Where the alleged duplicity in the charge is latent, it may only be manifested by the way in which evidence is presented to support the charge. It may not be until the prosecution's case is concluded that it becomes apparent that the prosecution cannot prove all of the acts that have been rolled together in a single composite charge, making plain the unsuitability of the process reliant on that charge. Exceptions to the general rule against duplicity have been allowed where the multiple acts relied on by the prosecution are so close in time and place that they can be viewed as one composite activity; where the offence is one that can be classified as continuing in nature; and in other anomalous cases. However, such cases apart, although the courts in England and New Zealand have taken a more lenient view, this Court has, until now, favoured a rule of strictness. The question is whether this Court should now soften that stance.[31]