R v Dubois and O'Dempsey

The case of R v Dubois and O'Dempsey involved the joint trial of two defendants who were charged with multiple offences including deprivation of liberty, murder, and rape. The charges stemmed from the same set of events, and the prosecution's case against each defendant largely depended on alleged confessions given to witnesses, whose credibility was in question. The court was required to determine whether the risk of prejudice from the inadmissible and highly prejudicial evidence could be mitigated by an appropriate direction to the jury, and whether a jury could effectively assess the credibility of a witness while ignoring corroborating evidence. Additionally, the court had to consider whether a joint trial would cause positive injustice to either defendant and whether separate trials should be ordered.

The legal issues before the court were significant, focusing on the principles of joinder and the potential for prejudice in a joint trial. The court had to assess whether the inadmissible evidence, which was prejudicial and corroborative of the key witnesses' testimonies, could be sufficiently controlled by a jury's ability to follow a direction to disregard it. Furthermore, the court needed to determine if there was a substantial risk that the joint trial would cause positive injustice to the defendants, which would warrant separate trials.

In delivering its decision, the court found that the risk of prejudice from the inadmissible evidence was too significant to be mitigated by any direction to the jury. The court concluded that a jury would likely find it difficult to ignore evidence that corroborated the key witnesses' testimonies. Additionally, the court determined that there was a substantial risk of positive injustice to each defendant if they were tried jointly, as the inadmissible evidence could unfairly bolster the credibility of the witnesses against both defendants. Consequently, the court ordered that the trial of each accused be heard separately, ensuring that each defendant received a fair trial without the risk of prejudice from the inadmissible evidence.