R v Cheng

This case concerned an appeal against a criminal conviction. The appellant, Mr Cheng, challenged the trial judge's decisions regarding the admissibility of evidence. The appeal was heard by Sulan, Peek, and Stanley JJ of the Supreme Court of South Australia.

The primary legal issues before the Full Court were whether the trial judge had adequately assessed the competence of a nine-year-old child witness, L, to give sworn evidence, and whether the judge had properly admitted a statement made by L under section 34CA(1) of the relevant Act. The Court also considered whether the admission of L's interview under section 34CA(1) was justified, given the circumstances and the probative value of the statement.

The Court held that the trial judge's dialogue with the child witness was insufficient to justify the decision that L was competent to give sworn evidence. Referencing *R v Starrett*, the Court emphasised that the legislative provisions concerning sworn and unsworn evidence are not mere formalities and require appropriate inquiries. The Court noted that while a child under 18 is not automatically presumed incompetent, children under ten, in particular, should undergo a section 9 inquiry to determine their capacity for sworn or unsworn evidence, even though they may not be capable of committing perjury. Regarding the admission of L's interview under section 34CA(1), the Court observed that the transcript suggested the judge had not adequately considered the circumstances of the statement or its probative value before admitting it.

Although the Court found that the inadequate assessment of the child witness's competence and the admission of the interview under section 34CA(1) were grounds for allowing the appeal, it noted that a new trial would be ordered on other grounds. Therefore, it was unnecessary to formally amend the grounds of appeal to include the issue of the child witness's competence. The Court made no comment on the procedure that followed the mistrial declaration.