O'Dea v Western Australia

The High Court of Australia heard an appeal by Mr O'Dea against his conviction for unlawfully doing grievous bodily harm with intent. The prosecution's case at trial relied on section 7(a) of the *Criminal Code* (WA), which deems a person who "actually does the act" constituting an offence to be guilty. The central dispute arose from uncertainty as to whether the appellant's actions, his co-accused's actions, or a combination thereof caused the grievous bodily harm. The trial judge directed the jury that they could convict the appellant if they were satisfied that he and his co-accused were "acting in concert, each of them doing one or more of the acts which caused" the harm, and that the relevant acts were unlawful.

The legal issues before the High Court were whether section 7(a) of the *Criminal Code* permits the acts of one person to be attributed to another, and whether the trial judge's direction to the jury occasioned a miscarriage of justice. The Court considered the historical context of section 7, noting that the *Criminal Code* was intended to replace common law principles of criminal liability, which distinguished between principals and accessories. The common law concept of a principal in the first degree involved those who "actually and with their own hands committed the act."

The High Court reasoned that section 7(a) requires proof that the accused person "actually does the act" that constitutes the offence. It rejected the notion that acts of one person could be attributed to another under this section, particularly in the absence of an allegation of a joint criminal enterprise or unlawful common purpose. The Court affirmed that the act causing the harm must be the "actual" act of the accused, not an attributed act. Consequently, the trial judge's direction that the appellant could be convicted based on a combination of his acts and his co-accused's acts while "acting in concert" was an error of law.

The appeal was allowed, the conviction was set aside, and a new trial was ordered. The Court clarified that the concept of "acting in concert" is not part of section 7(a) and should not be included in directions to the jury concerning that provision. Instead, for a conviction under section 7(a) where harm results from multiple individuals' acts, it must be proven that the accused's own acts were sufficient to cause the harm and were not undertaken in self-defence or due to an honest and reasonable mistake.