Aytugrul v The Queen

The High Court of Australia considered an appeal by the appellant, Aytugrul, against his conviction for murder. The central dispute concerned the admissibility of expert evidence relating to mitochondrial DNA analysis of hair found on the deceased's thumbnail. The prosecution's expert witness presented statistical findings in the form of both a frequency ratio and an exclusion percentage.

The legal issues before the High Court were whether the evidence of the exclusion percentage was relevant, given the evidence of the frequency ratio, and whether its probative value was outweighed by the danger of unfair prejudice to the appellant, as contemplated by sections 135 and 137 of the *Evidence Act*. The court also considered whether the evidence of the exclusion percentage was misleading or confusing, and whether judicial notice could be taken of psychological research to support a general rule that exclusion percentage evidence is inadmissible due to unfair prejudice.

The High Court reasoned that the appellant had not demonstrated that the probative value of the exclusion percentage evidence was outweighed by the danger of unfair prejudice. Consequently, neither section 135 nor section 137 of the *Evidence Act* was engaged in a manner that would render the evidence inadmissible. The court found no error in the admission of this evidence at trial.

The appeal was dismissed.