The High Court has allowed four appeals from a judgment of the Full Court of the Supreme Court of South Australia on jury procedures. After it emerged that the jury foreman may have misunderstood the trial judge’s question about whether or not ten or more of the jury had voted to find the appellants not guilty of murder, the DPP applied for orders to expunge or quash those verdicts, the judgment of acquittal, and the alternative convictions of manslaughter returned by the jury, and an order for a new trial on the murder charges. A majority of the SASCFC granted that application, partly on the basis of affidavits obtained from each of the former jurors and admitted into evidence in part by the Full Court, and held that it had inherent jurisdiction to make those orders. Before the High Court, the appellants sought to argue that evidence of former jury deliberations is inadmissible, and that the Full Court lacks inherent jurisdiction to set aside a jury verdict of acquittal.

The Court unanimously allowed the appeals. The plurality (French CJ, Kiefel and Bell JJ) held that the only arguable source of power to alter or set aside a jury verdict after the discharge of a jury without recalling it was the inherent power of the Court, and that in this matter, that power did not extend to support orders quashing the verdicts and directing that there be a new trial (at [5]). Although inherent power is difficult to define (see discussion at [67]ff), it generally means the powers of a court that are necessary to ensure it can effectively exercise its jurisdiction. Here, the verdict delivered by the foreperson, despite the error, were translated by the trial judge into perfected judgments of acquittal and conviction; this put amending those judgments beyond the inherent powers of the court. The powers to correct orders that have been drawn up and perfected by the court is very limited, and while it extends to correcting an order so that it reflects what the court did or intended to pronounce (the ‘slip rule’), it does not allow the court to reconsider or alter the actual result that was reached and recorded (see [71]). Here, because the judgments of acquittal and conviction were entered by the trial judge acting on the jury’s verdicts, there was no error and the slip rule does not apply (at [71). The plurality also rejected the Full Court’s use of a ‘wide concept’ of abuse of process: that concept, while wide enough to cover and respond to any means of misusing a court’s processes, does not extend to innocent errors by a jury foreperson in delivering a verdict (see at [74]). Finally, because of this lack of inherent power, the court was not able to admit the affidavit evidence about the mistake (see [80]ff).

Nettle and Gordon JJ agreed with the orders of the plurality, but held that the question of the inherent powers of a court to set aside a perfected judgment on the basis that the underlying jury verdict was incorrect was not reached here: the verdicts in this matter remained inviolable because the only evidence that was relied on to demonstrated the alleged error was inadmissible (at [102]). Evidence of jury room deliberations are generally inadmissible (see at [103]ff). Here, the statements at most showed that some of the jurors may not have understood the law properly, but that all of them agreed in the verdicts given court; despite possible misapprehensions, the general rule still applied because it would offend the inviolability of the finality of the verdict (see at [111]–[112]).