R v Porter

In this case, Bertram Edward Porter was tried on indictment for murder before Dixon J. in the original jurisdiction of the High Court. The charge arose from the death of the accused's infant son, to whom the accused had administered strychnine, after which the accused had attempted to take his own life. The defence raised was that the accused was insane at the time of the act.

The legal issues before the court were whether the accused had committed the act of murder, and if so, whether he was criminally responsible for his actions due to unsoundness of mind at the time of the offence. The court was required to instruct the jury on the respective burdens of proof for these elements. Specifically, the jury had to determine if the Crown had proven beyond reasonable doubt that the accused administered strychnine with the intention of causing death and that death resulted from this act. If this was proven, the jury then had to consider whether the defence had established, on a balance of probabilities, that the accused's mental state rendered him criminally irresponsible.

Dixon J. directed the jury that every person is presumed to be of sound mind for criminal responsibility unless the contrary is made to appear. The burden rests on the defence to establish insanity on a balance of probabilities, not to the exclusion of all doubt. The judge explained that legal insanity requires a disease, disorder, or disturbance of the mind that prevents the accused from knowing the physical nature of the act or knowing that the act was wrong. He clarified that "wrong" refers to the everyday standards of reasonable people and that the disorder must be such that the accused is incapable of rationally considering the reasons that make an act right or wrong. The jury was instructed to consider outward actions and medical opinion to assess the accused's mental state at the critical time of the offence.

The jury returned a verdict of not guilty on the ground of insanity at the time of the commission of the act charged.