Eroding jury unanimity

In R v Siloata 14/7/04, CA477/03 the NZCA held that when the presumption of purpose of supply applies upon proof that the accused had possession of a particular quantity of drug, the accused has to disprove that purpose to the unanimous satisfaction of the jury: there is no room for disagreement among jurors about this. If one juror thinks the accused has not satisfied the burden of proof then all jurors must find him guilty.

The Court said that to hold otherwise would defeat the reason for having the statutory presumption of purpose.

Unfortunately, the Court's reasoning means that the presumption cannot be used unless all jurors agree that the accused had possession of the necessary quantity of drug. This disadvantages the prosecution. The Court's reasoning confuses the fact-finding role of individual jurors (each of whom should be able to use the presumption if they find the necessary preliminary fact proved) with the verdict-finding role of the jury as a whole (which has to be agreed on its verdict).

Update: readers will be pleased to note that the Supreme Court has overruled the Court of Appeal's decision on this point: Siloata v R 16/12/04, SCC CRI 8/2004.