R v MK

Citation: R v MK [2012] NSWCCA 110
Court: NSW Court of Criminal Appeal
Date: 4 June 2012
Judges: Hoeben JA, Hidden J, Beech-Jones J (judgment delivered by Beech-Jones J)

Background

The respondent faced charges of detaining a child for advantage and two counts of aggravated indecent assault on a child under 16, all alleged to have occurred on 6 February 2011. The Crown's case was largely circumstantial: a vehicle registered to the respondent was seen at the scene, and both child witnesses described an offender with cheek piercings consistent with the respondent's appearance. No adult witness identified the respondent directly.

Following medical examination of the six-year-old complainant on the night of the alleged offences, swabs were taken for DNA testing. Analysis of the complainant's underpants and shorts by the Division of Analytical Laboratories produced results indicating that the respondent could not be excluded as a contributor to a mixed DNA profile.

At a pre-trial voir dire (a hearing to determine the admissibility of evidence before trial), the trial judge, Judge Nicholson SC, excluded the DNA evidence under sections 135(b), 135(c) and 137 of the Evidence Act 1995, finding it was prejudicial and misleading. The Crown appealed that ruling to the Court of Criminal Appeal under section 5F(3A) of the Criminal Appeal Act 1912.

Legal Issues

• Whether the trial judge erred in excluding the DNA evidence as unfairly prejudicial or misleading under sections 135 and 137 of the Evidence Act 1995
• Whether the trial judge's reasoning was infected by the same error identified in Aytugrul v R, namely placing undue weight on the form of the statistical frequency ratio used to express the DNA match probability
• Whether the exclusion of the DNA evidence substantially weakened the prosecution case, so as to satisfy the threshold for a Crown appeal under section 5F(3A) of the Criminal Appeal Act 1912

Decision

The Court of Criminal Appeal found that the trial judge's reasoning was flawed in a manner consistent with the error identified in Aytugrul v R [2012] HCA 15. In that case, the High Court confirmed that the form in which a DNA frequency ratio is expressed (for example, whether as "1 in 630" or as a percentage) does not, of itself, render the evidence inadmissible or unfairly prejudicial. The trial judge had placed excessive weight on the relatively low frequency ratio of approximately 1 in 630 unrelated males, and this materially infected the exercise of the discretion to exclude.

Beech-Jones J acknowledged that other doubts about the DNA evidence had been raised during the voir dire, including questions about the assumptions underlying the analyst's methodology. However, these concerns had not been fully explored, and the Court was not satisfied that the evidence must have been rejected in any event on those other grounds.

On the statutory threshold for a Crown appeal, the Court was satisfied that the exclusion of the DNA evidence had substantially weakened the prosecution case. The DNA results formed an important plank in what was otherwise a circumstantial identification case, and their rejection met the test under section 5F(3A).

The Court was careful to note that its decision to allow the appeal did not foreclose further challenges to the DNA evidence at trial. Remaining questions, including whether the two assumptions adopted by the analyst could be supported and whether the Y-filer results would be meaningful if those assumptions failed, were left open for reconsideration. The Court also noted that, if those assumptions could not be established, the evidence might not even satisfy the basic relevance threshold under section 55 of the Evidence Act 1995, before any discretionary exclusion arose.

Orders Made

• Appeal allowed.
• The judgment of Judge Nicholson SC, dated 19 March 2012, be set aside.

Key Takeaways

• The Court of Criminal Appeal confirmed that a low DNA frequency ratio (here, approximately 1 in 630 unrelated males) does not, without more, justify the exclusion of DNA evidence as unfairly prejudicial or misleading. Overemphasis on the ratio's form or magnitude, without proper analysis of probative value, constitutes an error in the exercise of the discretion under sections 135 and 137 of the Evidence Act 1995.
• Allowing the Crown appeal required satisfaction that the evidentiary ruling had "eliminated or substantially weakened" the prosecution case, assessed on the assumption the jury would accept the evidence, and without weighing credibility or reliability. The Court found that threshold was met here because the DNA evidence was a significant element of a circumstantial identification case.
• A successful Crown appeal under section 5F(3A) does not finally determine the admissibility of the disputed evidence at trial. The Court expressly preserved the respondent's right to mount fresh challenges, including on the underlying assumptions of the DNA analysis and on relevance under section 55.
• Where methodological assumptions underpinning DNA evidence cannot be supported, the evidence may fail to satisfy basic relevance requirements under section 55 of the Evidence Act 1995 before any discretionary exclusion under sections 135 or 137 is even engaged.
• Insufficient exploration of evidentiary challenges during a voir dire, particularly when argument focuses narrowly on one aspect of the evidence, may leave significant questions unresolved and affect the Court's ability to determine whether exclusion was inevitable.

Legislation and Cases Referenced

Legislation:
- Crimes Act 1900 (NSW), ss 61M(2), 86(1)(b)
- Criminal Appeal Act 1912 (NSW), s 5F
- Evidence Act 1995 (NSW), ss 55, 135, 137

Cases:
- Aytugrul v R [2010] NSWCCA 272; (2010) 205 A Crim R 157
- Aytugrul v R [2012] HCA 15; (2012) 86 ALJR 474
- House v The King (1936) 55 CLR 499
- Morgan v R [2011] NSWCCA 257
- R v Shamouil [2006] NSWCCA 112; (2006) 66 NSWLR 228