Conversation at 15.37 on 11 September 2003 - "In this conversation the word 'clothes' I'm of the opinion that the word 'clothes' here is referring to heroin".
32 On this appeal counsel for the appellant did not dispute that Sgt Nguyen could properly give some evidence which would have been based on his specialised knowledge. It was not disputed that Sgt Nguyen could give evidence that persons engaged in drug dealings often speak to each other in a kind of code or cryptic language, in which words and expressions which do not ordinarily refer to drugs are used by the speakers to refer to drugs. He could also give evidence that certain particular words and expressions, which do not ordinarily refer to drugs, are commonly used by drug dealers to refer to drugs.
33 However, it was submitted by counsel for the appellant, Sgt Nguyen could not give evidence that, in his opinion, particular words and expressions used in an intercepted conversation were in fact being used by the speakers to refer to drugs. Such an opinion could only have been formed by Sgt Nguyen on a basis which included other facts, apart from the mere use of the word or expression. For example, an opinion that the word "fridge" as used in a conversation was being used to mean heroin could not have been formed by Sgt Nguyen, simply on the basis of the use of the word "fridge", because, as is obvious, there will be many conversations in which the word "fridge" has its ordinary literal meaning, that is "refrigerator".
34 A conclusion that in a particular conversation the word "fridge" meant heroin could have been formed, only if there were other facts, apart from the use of the word "fridge" in the conversation, supporting a conclusion that the parties to the conversation were talking about heroin, for example, other facts police had gathered about the parties to the conversation indicating that the parties to the conversation were engaged in supplying heroin. However, in such circumstances, an opinion that the word "fridge" meant heroin would not be based wholly or substantially on the witness's specialised knowledge and hence would not be admissible under s 79 of the Evidence Act. Furthermore, the other facts on which Sgt Nguyen's opinion was based were not identified in his evidence and Sgt Nguyen had not disclosed any process of reasoning by which he had arrived at his opinion. Insofar as the further facts on which Sgt Nguyen had based his opinions were elicited in cross-examination, this confirmed that his opinions were not based wholly or substantially on his specialised knowledge.
35 In its written submissions the Crown, while opposing the allowing of the appeal against conviction, accepted that Sgt Nguyen should not have given evidence in the form in which he had and that it had become evident at the trial, particularly in cross-examination of Sgt Nguyen, that Sgt Nguyen had, at least in part, inappropriately allowed other information he had received to form part of the basis for his opinions.
36 On the hearing of the appeal the Court was referred to a number of cases, including R v David and Gugea (unreported NSWCCA 10 October 1995), R v Huynh (unreported NSWCCA 13 May 1996), R v Lam (2002) 135 A Crim R 302 and Keller v R [2006] NSWCCA 204.
37 In David & Gugea, a case to which the Evidence Act 1995 did not apply, the evidence against each of the appellants, who had been charged with offences of supplying drugs, consisted mainly of conversations which had been recorded through telephone intercepts or listening devices. The conversations were in the Romanian language and literal translations into English had been made, the accuracy of which was not disputed. It was the Crown case that the conversations related to the supply of heroin. The appellants made unsworn statements at the trial denying that the conversations related to the supply of heroin and asserting that the conversations related to the purchase of gold and brandy and the supply of women for prostitution.
38 According to the ordinary literal meaning of the words used in the conversations, the conversations did not relate to the supply of drugs. However, evidence was given at the trial by a police officer (Sgt Drury) and an analyst and interpreter with the New South Wales Crimes Commission (Mrs Kandic) in which they expressed the opinion that the subject matter of the recorded conversations was in fact the supply of heroin.
39 In its judgment the Court of Criminal Appeal concentrated on the evidence given at the trial by Sgt Drury. The Court held that Sgt Drury, by virtue of his experience in drug law enforcement, was qualified to give expert evidence about the drug trade, notwithstanding that he relied not only on his personal experience but also, to some extent, on hearsay material. The Court continued :-
"He was entitled as an expert to give evidence that persons trafficking in illicit drugs never (or almost never) refer to drugs directly, even by the names such as 'speed' or 'crack' by which they are often known; rather, that illicit drug traffickers usually speak in a disguised manner (or in a code) in order to avoid anyone overhearing them becoming aware that they are discussing such activities, and (where relevant) as to the particular codes often adopted (the argot). None of that was in dispute in these appeals. What was in dispute was whether Sgt Drury was entitled to go further and give evidence that, in his expert opinion, the subject matter of these particular recorded conversations was in fact the supply of heroin".
40 The Court concluded that, provided the witness explained how he had reached his opinion, an expert such as Sgt Drury would be entitled to give evidence that the conversations could be referring to the supply of heroin. However, he would not be entitled to give evidence that the conversations in fact referred to the supply of heroin. One objection to evidence being given in such a form was that it was liable to so influence a jury "that they would not trouble to make up their own minds".
41 As the evidence given by each of the witnesses was in the form of an opinion that the subject matter of the recorded conversations was in fact the supply of heroin, the appeal against conviction was allowed.
42 David & Gugea was distinguished in Huynh, which was another case to which the Evidence Act did not apply. In Huynh the evidence against the appellant, who was charged with conspiring to supply heroin, included tape recordings of conversations. In the conversations the speakers sometimes specifically referred to heroin by name. At other times in the conversations language not literally referring to heroin was used but in contexts where there was discussion about prices, values at wholesale or street level, measurements and quantities and the mixing or diluting of the primary substance which was for sale.
43 In Huynh two witnesses with long experience in the investigation of drug trafficking (an officer of the Independent Commission against Corruption in Hong Kong and a police officer) gave evidence for the Crown, including evidence that in their opinions in particular parts of the conversations the parties were in fact talking about heroin.
44 The Court of Criminal Appeal held that the evidence of the expert witnesses was admissible and dismissed the appeal against conviction. The Court distinguished David & Gugea on the grounds that in David & Gugea there had not been, as there had been in Huynh, "all the background material, including the discussion of weights, measures, quantities and the like and specific discussion of drug dealing and heroin… here the evidence, apart from the opinion evidence, showed that the appellant was a dealer in heroin".
45 In Lam Sgt Drury, the same witness who had given evidence in David & Gugea, gave expert evidence about what the Crown alleged were coded drug conversations. It would appear that, subject to one exception which was not the subject of any objection, Sgt Drury gave evidence in the form that certain words and expressions used in the conversations were consistent with, and could be references to, illicit drug dealing and not in the form that words and expressions used in the conversations did not in fact have their literal meanings and in fact referred to illicit drug dealing.
46 No objection was taken by counsel for Lam at the trial to any of the evidence given by Sgt Drury and the Court of Criminal Appeal disposed of the relevant ground of appeal against conviction by applying r 4 of the Criminal Appeal Rules.
47 The Evidence Act applied to the proceedings in Lam. Levine J, who gave the leading judgment in the Court of Criminal Appeal, referred to, and would appear to have accepted, a submission by the Crown that the legal position stated in David & Gugea continued to apply after the coming into force of the Evidence Act.
48 The appeal to this Court in Keller was heard and determined after the trial of the appellant in the present appeal, so that the trial judge in the present proceedings did not have the benefit of having this Court's judgment in Keller.
49 In Keller the Crown alleged that Keller had agreed to purchase cocaine from a man named Purdie. The Crown case against Keller was largely based on intercepted telephone conversations between Keller and Purdie, which the Crown alleged were concerned with the making of arrangements between Keller and Purdie for the supply of cocaine. The appellant gave evidence at the trial in which he asserted that the conversations between himself and Purdie were about the purchase of a motor vehicle and had nothing to do with the supply of cocaine.
50 At the trial an Australian Federal Police officer named Smith, who had had training and experience in the investigation of drug offences, gave evidence in the Crown case of opinions he had formed about the meaning of various words used in the intercepted conversations between Keller and Purdie. The evidence Mr Smith gave included evidence to the effect that certain words and expressions used in the conversations were in fact references to drugs. That the witness's evidence in the trial was given in this form was somewhat surprising, because in a statement by him which was the principal evidence in a voir dire inquiry held to determine the admissibility of his evidence, he had confined himself to expressing opinions that words used in the conversations were "consistent with" being references to drugs.
51 The leading judgment in the Court of Criminal Appeal in Keller was given by Studdert J, with whom the other members of the Court agreed.
52 In par 23 of his judgment Studdert J said, in part, that counsel for the appellant had conceded, in Studdert J's view correctly, that "if the witness had limited himself to expressions of opinions as to the consistency of the language used being referable to a drug dealing, the appellant would have no complaint". However, as Studdert J observed (at par 33 of his judgment) the witness had failed to distinguish "between an expression of opinion that something spoken was consistent with being a reference to drugs and asserting that something was a reference to drugs".
53 In par 29 of his judgment Studdert J said:-
"29 It seems to me that in a situation such as occurred in the present case where a witness is expressing evidence that the speaker was talking about drugs, it is necessary that there be a manifest foundation for the evidence, namely:
(i) that it should be made apparent that the opinion expressed 'is wholly or substantially based' upon the expert training, study or experience of the witness: s 79 (of the Evidence Act):
(ii) that the reasoning process of the witness should be sufficiently exposed to enable an evaluation as to how the witness used his expertise in reaching his opinion".
54 With regard to (ii), Studdert J referred (at par 31 of his judgment) to the frequently quoted passage in the judgment of Heydon JA (as his Honour then was) in Makita (Australia) Pty Limited v Sprowles (2001 52 NSWLR 705 at 744 (85).
55 In his judgment Studdert J discussed David & Gugea and Huynh and concluded that "the differing outcomes in David & Gugea and Huynh highlight the necessity for a close consideration of the circumstances of the particular case" (at par 42).
56 In par 42 of his judgment Studdert J concluded that the requirements for admissibility which he had earlier stated in par 29 of the judgment were not satisfied. His Honour said:-
"….I do not consider it has been shown that the opinions expressed by the witness were wholly or substantially based upon his specialised knowledge. Further, I do not consider that the reasoning process of the witness has been sufficiently exposed to establish how his conclusion was based upon his specialised knowledge, if such be the case…".
57 Consequently, the evidence from Mr Smith was held not to be admissible as evidence of opinions based on specialised knowledge under s 79 of the Evidence Act.
58 Studdert J added that, even if the evidence had been admissible under s 79, the evidence should have been excluded under s 137 of the Evidence Act, because its probative value was outweighed by the danger of unfair prejudice. There was a real risk that the jury would be distracted from making its own assessment of the evidence of the conversations by the evidence of the police officer of his opinions that the conversations were about drugs and, as the reasoning process of the police officer in forming his opinions had not been properly disclosed, the jury were not in a position properly to assess the validity of the police officer's opinions.
59 After this consideration of the authorities to which the Court was referred, I turn to a consideration of the circumstances of the present appeal.
60 As is apparent from the parts I have quoted, the evidence of Sgt Nguyen about the meanings of words and expressions used in the intercepted conversations, both in the statement of facts which was the principal evidence in the voir dire inquiry and in the evidence Sgt Nguyen gave in the trial, was in the form of opinions by Sgt Nguyen, not that words and expressions used in the conversations could be references to drugs or were consistent with being references to drugs, but that the words and expressions were in fact references to drugs.
61 Evidence in this form was held inadmissible by this Court in David & Gugea and Keller. Huynh can be distinguished from the present case in that there were not in the intercepted conversations in the present case explicit discussion of weights, measures and quantities and uncoded references to drug dealing and heroin.
62 The evidence by Sgt Nguyen was not admissible under s 79 of the Evidence Act as evidence of opinions wholly or substantially based on the witness's specialised knowledge, because, as is clear, Sgt Nguyen's opinions that words or expressions were in fact references to drugs were based, to a substantial extent, on matters other than his specialised knowledge, including information about the activities of the appellant which had been conveyed to him by police participating in the police investigation.
63 Further reasons why the evidence by Sgt Nguyen was not admissible as evidence of expert opinion were that not all of the facts on which Sgt Nguyen's opinions were based were identified in his evidence and Sgt Nguyen failed to disclose the reasoning process by which he had arrived at his opinions. Makita v Sprowles; Keller v R.
64 To the limited extent to which the facts on which Sgt Nguyen's opinions were based were identified and the reasoning process by which he had arrived at his opinions was disclosed, this served to confirm that his opinions were not wholly, or even substantially, based on his specialised knowledge.
65 Furthermore, the evidence in the form in which it was given, even if it had been admissible under s 79, should have been excluded under s 137 of the Evidence Act on the ground that its probative value was outweighed by the danger of unfair prejudice to the appellant, in that the evidence was liable to so influence a jury as to distract it from making its own assessment of the evidence of the intercepted conversations.
66 I would allow the first ground of appeal.