R v McCarthy

The defendant appealed his conviction for murder to the Full Court of the Supreme Court of South Australia. The grounds of appeal primarily concerned alleged omissions and deficiencies in the trial judge's summing up to the jury, as well as claims that the judge should have exercised discretion to exclude certain evidence and that the conviction was unreasonable and unsupported by the evidence.

The court was required to determine several legal issues, including whether the trial judge had adequately directed the jury on the defence of self-defence, the partial defence of provocation, and the interplay between the element of intention and the defendant's intoxication. Further issues included complaints arising from the prosecution's presentation of two alternative cases (a "striking case" and an "asphyxiation case"), directions given in respect of the defence case, the admission of evidence of conversations between the defendant and police, and whether the verdict was unreasonable.

The court considered the principles governing a judge's summing up, noting that its role is to crystallise legal issues and simplify the jury's task of applying the law to the facts. It is not necessary for a judge to identify every piece of evidence or argument relevant to the defence, but the respective cases for the prosecution and the accused must be accurately and fairly put to the jury. The court also examined the provisions of section 15 of the Criminal Law Consolidation Act 1935 (SA) concerning self-defence, which distinguishes between complete and partial defences based on the proportionality of the conduct to the perceived threat. The appeal was allowed, and a new trial was ordered.