Citation: [2015] NSWDC 424
Court: District Court of New South Wales
Date: 30 July 2015
Judge(s): Yehia SC DCJ
Background
Three accused faced charges under section 24(2) of the Drug Misuse and Trafficking Act 1985 (NSW) relating to the manufacture of, or knowing participation in the manufacture of, methylamphetamine in a large commercial quantity at a Bringelly property between 14 and 26 June 2013. All three entered pleas of guilty to manufacturing the drug, but disputed that the quantity reached the large commercial threshold. The Crown did not accept those limited pleas in full satisfaction of the indictment.
To establish the quantity element, the Crown relied partly on circumstantial evidence from a clandestine laboratory discovered at the Bringelly premises and partly on expert opinion evidence from a forensic chemist, Ms Ellam. Ms Ellam opined that 273 kg of alkaline brown liquid found in 15 vessels at the site was waste product from the manufacture of methylamphetamine, and that applying a conservative ratio of 100:1 (waste product to yield) produced an estimated yield of at least 2.7 kg.
The accused objected to the admissibility of the ratio-based opinion under section 79 of the Evidence Act 1995 (NSW), and in the alternative sought its exclusion under sections 135 and 137.
Legal Issues
- Whether Ms Ellam's opinion applying a 100:1 waste-to-yield ratio satisfied the requirements of section 79 of the Evidence Act, specifically whether the opinion was wholly or substantially based on specialised knowledge derived from her training, study or experience
- Whether reliability is a relevant consideration when determining admissibility under section 79
- Whether reliability may be taken into account when assessing probative value under sections 135 and 137 of the Evidence Act
- Whether the evidence should in any event be excluded under sections 135 or 137
Decision
Issue 1: Admissibility under section 79
The court accepted that Ms Ellam possessed genuine specialised knowledge as a forensic chemist, based on her qualifications and her experience attending over 130 clandestine drug laboratories (at [82]-[83]). It also accepted, in principle, that there may be a recognised field of specialised knowledge concerning the estimation of likely ratios between waste product and yield in methylamphetamine manufacture (at [84]). The critical question was whether her specific opinion about yield in this case was sufficiently grounded in that specialised knowledge (at [85]).
The court found the opinion fell short of that requirement on multiple grounds. The 100:1 ratio derived from colleagues who transmitted the figure during training, but Ms Ellam did not know the cases or underlying material supporting their view (at [88]-[89]). Her experience of four or five controlled laboratory manufacture sessions did not include any recording of waste-to-yield ratios (at [90]). Her crime scene experience did not supply sufficient detail about the methods, proportions, or calculations used on those occasions (at [91]). Reliance on internet recipes and illegal manufacture booklets did not constitute a proper scientific basis (at [92]), and the mere fact that colleagues used the same ratio in other reports did not establish how it was formulated (at [93]).
Critically, the opinion was proffered in the absence of any information about the amounts of precursor chemicals used, the number of extraction processes undertaken, or the purity and proportions of compounds in the waste product (at [94]). The opinion was not based on scientific formula, scientific literature, or analysis of the chemical compounds involved (at [95]-[96]). The court concluded that the evidence did not satisfy section 79 and was therefore inadmissible in that respect (at [99]).
Issue 2: Reliability under section 79
Consistent with the preponderance of NSW and Victorian appellate authority, the court held that reliability is not a relevant consideration when determining admissibility under section 79 (at [69]-[77]). The court expressly confirmed that it excluded the ratio opinion without reference to reliability considerations (at [99]). The court did, however, observe that the concept of "knowledge" in section 79, as defined by reference to Daubert and endorsed by the High Court in Honeysett, connotes more than subjective belief or unsupported speculation and applies to any body of known facts or ideas inferred from such facts and accepted as truths on good grounds (at [101]-[105]).
Issue 3: Reliability under sections 135 and 137
The court noted that in New South Wales, established authority holds that reliability cannot be taken into account by a trial judge when assessing the probative value of evidence under sections 135 and 137 (at [112]). This meant that the assurance provided in Tuite v The Queen, that reliability could be rigorously assessed at the section 137 stage, was not fully available in New South Wales. The court expressed the view that appellate courts would need to give this proposition more detailed consideration (at [115]). Having excluded the opinion under section 79, the court did not need to exercise the discretion under sections 135 or 137, but noted that had the evidence been admissible under section 79, it would not have excluded it under those provisions (at [116]).
Orders Made
Admissibility of expert evidence.
Key Takeaways
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The District Court confirmed that, for expert opinion evidence to satisfy section 79 of the Evidence Act, it is not enough that a witness possesses general specialised knowledge in a field: the specific opinion expressed must be shown to be wholly or substantially based on that knowledge, with the underlying facts and reasoning made transparent (at [85], [97]-[99]).
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Where an expert's opinion rests on ratios or estimates passed on by colleagues during training, without any identifiable underlying cases, data, or scientific literature, that opinion lacks the necessary foundation to constitute specialised knowledge, even if the expert is otherwise highly qualified (at [88]-[89]).
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Reliability of an expert opinion is not a consideration in determining admissibility under section 79, consistent with the approach in Tang and affirmed in Tuite v The Queen, but this does not mean an opinion unsupported by transparent scientific criteria or proper factual foundation will be admitted (at [69]-[77], [99]).
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In New South Wales, reliability cannot be taken into account when assessing probative value under sections 135 and 137, a position that the District Court observed sits uneasily with the recognised importance of rigorous reliability assessment to the integrity of the criminal justice system, and which may warrant further appellate scrutiny (at [112]-[115]).
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Under the Daubert formulation endorsed by both the NSW Court of Criminal Appeal in Tang and the High Court in Honeysett, "knowledge" in section 79 connotes more than subjective belief or unsupported speculation: it applies to any body of known facts or ideas inferred from such facts and accepted as truths on good grounds (at [76], [101]).
Legislation and Cases Referenced
Legislation
- Evidence Act 1995 (NSW) ss 79, 135, 137
- Drug Misuse and Trafficking Act 1985 (NSW) s 24(2)
Cases
- Dasreef Pty Ltd v Hawcher [2011] HCA 21
- Daubert v Merrell Dow Pharmaceuticals 509 US 579 (1993)
- Dupas v The Queen [2012] VSCA 328
- Hannes v The DPP [2006] NSWCCA 373
- Honeysett v The Queen [2014] HCA 29
- Kumho Tire Co Ltd v Carmichael 526 US 137 (1999)
- Makita Pty Ltd v Sprowles (2001) 52 NSWLR 705
- Regina v Shamouil [2006] NSWCCA 112
- R v Burton [2013] NSWCCA 335
- R v Tang [2006] NSWCCA 167
- R v XY [2013] NSWCCA 121
- Tuite v The Queen [2015] VSCA 148