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Supreme Court 4 November 2022

R v Bowie (No 1)

[2022] NSWSC 1502

Homicide

Citation: R v Bowie (No 1) [2022] NSWSC 1502
Court: Supreme Court of New South Wales
Date: 4 November 2022
Judge: Yehia J

Background

The accused stood trial for the murder of his wife, Roxlyn Bowie, who disappeared from the family home in Walgett on 5 June 1982 and has not been seen or heard from since. The Crown case was entirely circumstantial: it alleged that the accused killed Roxlyn sometime between 7:00 pm and 11:00 pm that evening, and that he disposed of her body by feeding it to pigs at a piggery located at the nearby Walgett Meat Works, where he was responsible for feeding the animals.

Because no body was ever recovered, the Crown sought to explain the absence of physical remains through expert evidence. Central to that case were alleged statements made by the accused over many years to various acquaintances and colleagues, in which he reportedly remarked that pigs "don't leave any evidence" or words to similar effect.

On the first day of trial, the Crown applied to adduce portions of a report prepared by Sergeant Lauren Atwood, dated 20 May 2021, as expert opinion evidence under s 79(1) of the Evidence Act 1995 (NSW). The defence objected on grounds of relevance, inadmissibility, and unfair prejudice.

  • Whether Sergeant Atwood's expert report was relevant under s 55 of the Evidence Act 1995 (NSW)
  • Whether the report satisfied the requirements for expert opinion evidence under s 79(1) of the Evidence Act 1995 (NSW), specifically whether the opinion was based on an identifiable area of specialised knowledge
  • If the first two thresholds were met, whether the probative value of the evidence was outweighed by the danger of unfair prejudice, warranting exclusion under s 137 of the Evidence Act 1995 (NSW)

Decision

The report and its experiment. Sergeant Atwood's report examined the effect of the domestic porcine digestive process on animal carcasses and human teeth. The experiment involved feeding pigs a slurry of cooked porcine and kangaroo carcass, exposing pigs to wounded and intact porcine carcasses, and introducing human teeth into the pigs' enclosures. Notably, the experiment did not use human flesh or bone. The court observed at the outset that there is no published peer-reviewed scientific research on the specific question of what remains when human remains are ingested by pigs.

Relevance. Yehia J found that the portion of Sergeant Atwood's evidence dealing with the capacity of pigs to digest human teeth to the point where identifiable remains become difficult to recover was relevant to the issue of how Roxlyn's body may have been disposed of without trace. However, the evidence went only to the digestibility of human teeth, not human flesh and bone. The court characterised the probative value of even the admissible portion as slight.

Section 79(1): Specialised knowledge. The court held that the evidence was inadmissible under s 79(1) because the Crown had failed to establish that the opinion was wholly or substantially based on an area of specialised knowledge. There was no peer-reviewed literature from which any conclusion could be drawn about whether findings from an experiment conducted using porcine and kangaroo carcasses were comparable to the question of whether pigs can effectively consume human flesh and bones to the point that identifiable remains would be difficult to recover. The critical gap was the absence of any scientific foundation linking the experimental results to the actual issue at trial.

Section 137: Unfair prejudice. Although the exclusion under s 79(1) was determinative, the court went on to indicate that, even if the admissibility threshold had been satisfied, the evidence would also have been excluded under s 137. The probative value of evidence derived from a single experiment was outweighed by the danger that a jury might give it disproportionate weight or misuse it.

Orders Made

• Evidence from Sergeant Atwood regarding pigs feeding on porcine and kangaroo carcasses is inadmissible pursuant to s 55 of the Evidence Act

• Evidence from Sergeant Atwood regarding pigs feeding on human teeth is inadmissible under s 79(1) of the Evidence Act

Key Takeaways

  • Under s 79(1) of the Evidence Act 1995 (NSW), an expert opinion must be wholly or substantially based on an identifiable area of specialised knowledge; the absence of peer-reviewed scientific literature on the specific question at issue is a significant obstacle to establishing that foundation.
  • A gap between the subject matter of an experiment and the fact in issue at trial can be fatal to admissibility, even where the experiment is methodologically conducted; here, the use of animal carcasses rather than human remains meant the findings could not be reliably transposed to the Crown's case theory.
  • Relevance under s 55 and admissibility under s 79(1) are distinct hurdles, and evidence may clear the first without satisfying the second.
  • Where expert evidence rests on a single experiment without broader scientific validation, courts may find that its probative value is outweighed by the risk of disproportionate weight being assigned by a jury, engaging the exclusionary discretion in s 137.
  • The decision reaffirms the principles from Dasreef Pty Ltd v Hawchar (2011) 243 CLR 588 and Honeysett v The Queen (2014) 253 CLR 122 that the connection between an expert's opinion and an established field of specialised knowledge must be clearly articulated and demonstrable.

Legislation and Cases Referenced

Legislation
- Crimes Act 1900 (NSW), s 18
- Evidence Act 1995 (NSW), ss 55, 79(1), 137
- Evidence Act 2008 (Vic), s 79(1)

Cases
- Dasreef Pty Ltd v Hawchar (2011) 243 CLR 588; [2011] HCA 21
- HG v The Queen (1999) 197 CLR 414; [1999] HCA 2
- Honeysett v The Queen (2014) 253 CLR 122; [2014] HCA 29
- IMM v The Queen (2016) 257 CLR 300; [2016] HCA 14
- Morgan v The Queen [2011] NSWCCA 257; (2011) 215 A Crim R 33
- Murphy v The Queen (1989) 167 CLR 94; [1989] HCA 28
- R v McIntyre [2001] NSWSC 311
- R v Mohan [1994] 2 SCR 9
- R v Tang (2006) 65 NSWLR 681; [2006] NSWCCA 167
- R v Trochym [2007] 1 SCR 239
- Tuite v The Queen (2015) 49 VR 196; [2015] VSCA 148
- Xie v The Queen (2021) 386 ALR 371; [2021] NSWCCA 1