HKSAR v. WONG SAU MING

FACC No. 5 of 2002

IN THE COURT OF FINAL APPEAL OF THE

HONG KONG SPECIAL ADMINISTRATIVE REGION

FINAL APPEAL NO. 5 OF 2002 (CRIMINAL)

(ON APPEAL FROM CACC NO. 85 OF 2001)

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J U D G M E N T

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Chief Justice Li:

1. A fundamental feature of a fair trial is the right to cross-examine witnesses. As Wigmore pointed out in his classic work on Evidence, for centuries, the policy of the common law system of evidence has been to regard the necessity of testing by cross-examination as a vital feature of the law. And he described it as "beyond any doubt the greatest legal engine ever invented for the discovery of truth". See Wigmore Vol V para. 1367 (1974 ed.).

2. This appeal raises questions concerning the proper limits of cross-examination as to credit in a criminal trial and the scope of exceptions to the general rule that evidence is not admissible to contradict answers given on cross-examination as to credit. In this appeal, one is only concerned with cross-examination as to credit on the ground of the veracity of the witness.

The Conviction

3. On 16 February 2001, after trial by judge (Deputy Judge McMahon) and jury, the appellant was convicted of the offence of trafficking in dangerous drugs consisting of a mixture containing 63.8 grammes of heroin hydrochloride. He was sentenced to 8 years imprisonment.

Prosecution's case

4. The prosecution's case depended essentially on the evidence of the 1st prosecution witness, Police Constable 3432 ("PW1"). On 5 October 1997, PW1 and six other police officers were engaged in a surveillance operation near Wong Tai Sin. They saw the appellant meeting a man named "Tong" and both of them getting into a taxi, driven by a man named "Li". The police officers travelling in police vehicles followed the taxi and later intercepted it. The appellant was told to get out. He was searched by PW1 and was allegedly found to have an open black plastic bag in the pocket of his jeans containing the substance later analysed to be the dangerous drugs in question. PW1 was the only witness who gave evidence that the drugs were found on the appellant. Tong and Li were searched by the 3rd prosecution witness, Police Constable 19847 ("PW3") and the 5th prosecution witness Police Constable 52767 ("PW5") respectively. Nothing incriminating was found on them or in the taxi.

Defence case

5. The appellant gave evidence. According to him, he happened to meet Tong who offered to give him a lift to Yaumatei in Li's taxi. After they were stopped by police, he was searched by PW1 but no drugs were found on him. But he saw that the 4th prosecution witness, Sergeant 17246 ("PW4") searched the taxi and found the black bag containing the heroin on the front seat. He immediately said he had nothing to do with it.

6. The appellant was then taken back into a police vehicle and driven to a parking bay opposite the Yaumatei Police Station. There, PW4 asked him if he had any information to give, and told him if he could manage to get someone to come out with dangerous drugs, then one case could be "swapped for another". The appellant said nothing. He was then taken by PW4 to meet the police inspector who asked him if he had any information to give. He said he could not contact that sort of person. He was then taken by PW4 to a police van. Inside the van were Tong, Li, PW1, PW5 and another police sergeant. PW4 then offered the appellant, Tong and Li a deal. He said that they were all doomed to be convicted, but if one accepted responsibility, the other two would be released; the punishment would be a "bind over" or a fine, and that the drugs were just "Hong Kong dollars" (a slang phrase meaning that the drugs were of low purity). The appellant spoke with Tong and Li. Tong said Li could not take the blame as it would affect his family. Tong then told the appellant that he should take the blame. As Tong was his triad big brother, he agreed to do so and became the scapegoat.

The earlier case

7. Having regard to the cases of the prosecution and the defence, the credibility of the police officers, particularly PW1, was obviously a critical matter at the trial in the present case.

8. For the purpose of attacking their credibility, counsel for the defence applied to the judge to admit in evidence the Summary of Evidence and the Reasons for Verdict in an earlier case, HKSAR v. Leung Tat-ming ("Leung"), NKCC 7674/1997 ("the earlier case"), and to allow cross-examination of the police witnesses based on such materials. The judge ruled in favour of the defence.

9. The earlier case was a trial before a magistrate. Leung, the defendant, was charged with trafficking in dangerous drugs. After trial, he was acquitted. A number of the police witnesses in the present case, namely PW1, PW3, PW4 and PW5, were also prosecution witnesses in the earlier case. It would appear that the offence was alleged to have taken place in October/November 1997 before 5 November 1997, that is, within a few weeks of 5 October 1997, the relevant date in the present case. The prosecution's case depended essentially on the evidence of PW1 which was to the effect that he arrested Leung and found a plastic bag containing dangerous drugs in his shirt pocket.

10. Leung's defence was that he was arrested by PW5 and PW3, not by PW1 who only took a cautioned statement from him after his arrest. He was searched but nothing was found on him. PW5 told Leung that "someone said you sold heroin and I have witness to that, if you have, you'd better take it out". Leung denied this. PW3 left them and came back with the drugs in question and alleged that they were Leung's. Later, after giving the cautioned statement, PW3 asked for the pager number of Leung. PW5 gave Leung his pager number and asked him to provide drug information. Later, Leung was paged by PW5. On returning the call, PW4 told him to come out. Leung refused. PW4 then threatened him that "When he was seen, he would be arrested every time."

11. The details of the earlier case were set out in the Summary of Evidence which should be set out in full. For convenience, the defendant will be referred to as "Leung" and the police officers will be referred to by their abbreviations in the present case, that is PW1, PW3, PW4 and PW5.

HKSAR v. Leung Tat Ming, NKCC 7674 of 1997
Summary of Evidence

"1. The prosecution was that :

(i) [Leung] was intercepted at the junction of Ferry Street and Shantung Street, Mongkok by [PW1]. Upon search, a transparent plastic bag, containing suspected dangerous drugs was found at the left shirt pocket of [Leung];

(ii) [Leung] was arrested and cautioned. Under caution, [Leung] said 'Ah sir, I have just received pay therefore I purchase more drugs for my own consumption so that it is cheaper.'

2. The Defence was that :-

(i) He was not arrested by [PW1] and he was just responsible to take a cautioned statement from him;

(ii) He was intercepted by [PW5] and [PW3]. He was taken to a lane where he was searched. Nothing was found;

(iii) [PW5] told [Leung] that 'some one said you sold heroin and I have witness to that, if you have, you'd better take it out'. [Leung] denied;

(iv) [PW3] left them and came back with the drugs in question and alleged that the drugs were [Leung's];

(v) [PW4] was called to the scene and then [Leung] was taken back to police station;

(vi) At the police station, [PW1] took a statement from [Leung];

(vii) After the statement, [Leung] went to the toilet. Inside the toilet, [PW3] asked for the pager number of [Leung]. [PW5] gave his pager's number to him so that if he had any drugs information, he would inform [PW5];

(viii) On 5th November 1997, [Leung] was paged by [PW5]. When [Leung] returned call, [PW4] asked [Leung] to come out. [Leung] refused. [PW4] then threatened [Leung] that 'When he was seen, he would be arrested every time.'"

12. The magistrate acquitted Leung. In his Reasons for Verdict, he concluded that after considering the prosecution's evidence, there are some dubious points in the case and therefore he gave the benefit of doubt to Leung. The Reasons for Verdict should be set out in full. Again for convenience, the same designations for "Leung" and the police officers, as were used for the Summary of Evidence, will be used. It will be necessary to examine the reasons in detail later in the judgment.

HKSAR v. Leung Tat Ming, NKCC 7674 of 1997
Reasons for Verdict

"I accept it was a fact that [Leung] was requested by the police to act as an 'informer'. [PW5] also admitted the same in his testimony. According to [PW5], he talked with [Leung] about something after [PW1] had taken a cautioned statement from him. [PW5] said he was not sure whether [PW1] was still present there that time. If [PW5's] testimony is true, that means [Leung] agreed to be his informer and gave him his pager number. At this stage, [Leung] had already been arrested, and as said in the allegations made by the prosecution for the case, were found in possession of dangerous drugs, and has admitted verbally to the charge after being cautioned by the police. As it shows, [Leung] would not have any benefits if he agreed to be the police's informer.

I have reservations as regards [PW5's] testimony. When he was asked by the defence counsel about his conversation with [Leung], he was trying to get away from the question by saying that he was not sure whether [PW1] was there at the scene. There were also contradictions in some other areas of [PW5's] testimony. For example, when the defence counsel pointed out to him that he or his colleagues had rung [Leung] about a week after the incident arranging an interview for him to meet [PW4], he denied such allegation. He even said up to today, he had not rung [Leung]. However, at another point, he agreed that (he) had talked with [Leung] on the phone. He said he was returning [Leung's] call. Why did [Leung] ring him? According to [PW5], he was told don't have any information to give right now. (I'll) call you if I've any later. I've reconsidered [Leung's] testimony as regards this area. When giving his testimony, [Leung] talked about the telephone conversation which shows clearly that he was not willing to be an informer. His attitude remained the same when he went to lodge a complaint with the CAPO later. In this respect, the possibility that [Leung's] version is true and is greater.

[PW5's] statement has an impact on that of [PW1]. As [PW1] said in his testimony, he had never left [Leung] until he brought [Leung] to see the duty officer and handed to him the dangerous drugs. If this is the case, I wonder why he said had not heard any conversation between [PW5] and [Leung]. In [Leung's] testimony, which I considered again, he said it was [PW5] and [PW3], who had intercepted him instead of [PW1]. If [PW3] was not playing an important role in this case nor was he taking part in anything special, why did [Leung] have such a deep impression of him and could even identify him in the ID Parade conducted four or five months later?

After considering all the testimonies of the prosecution, I conclude that there are some dubious points in the case. Therefore, I'll give this benefit of doubt to [Leung] and [Leung] is not guilty of the charge."

The Judge's ruling

13. In his ruling admitting the Summary of Evidence and the Reasons for Verdict in the earlier case and allowing cross-examination by reference to such materials, the judge stated:

"It seems to me to fall squarely within the principle of Edwards' case as further approved by R v. Lam Wai Keung (1994) HKLR 9. In my view, the complaint as to misconduct in [the earlier case] by both witnesses is sufficiently close in its nature to the complained of conduct in the present case so as to make the expressed disbelief of the magistrate of their evidence in that case relevant to their credit in this case."

In fact, the judge had made a ruling of a similar nature in an earlier High Court case. The same counsel appeared for the defence in that case and in the present case. In the present case, the prosecution and defence agreed there was no need for the matter to be re-argued and a similar ruling should be made.

The Judge's summing up

14. In his summing up, the judge referred the jury to the Summary of Evidence and the Reasons for Verdict in the earlier case. He directed them:

"Bear in mind it is a matter for you to decide to what extent the magistrate disbelieved those witnesses on that previous occasion. It is also a matter for you to decide to what extent, if at all, the magistrate's disbelief of the witnesses in that case undermines their credibility in the present case."

By this direction, the approach which the jury was asked to adopt to the acquittal in the earlier case was that they should first decide to what extent the magistrate had in fact disbelieved the police officers. And they should then decide "to what extent, if at all" the magistrate's disbelief undermined their credibility in the present case.

The Court of Appeal

15. The Court of Appeal (Stuart-Moore VP and Stock JA, Cheung JA dissenting) dismissed the appellant's appeal.

(a) Stuart-Moore VP had considerable doubt that the judge had been right to admit the materials in the previous case as it was far from clear that the evidence of the three police officers concerned had been demonstrated to have been disbelieved. On the basis of this view, he held that the judge's direction inviting the jury to decide the extent to which the magistrate had in fact disbelieved the officers was unobjectionable. Having admitted the materials, they had to be examined on a true factual basis. If the judge had directed the jury that the magistrate had disbelieved the officers, this would not have summarised the true factual position. The defence had benefited from an over-generous ruling admitting the materials.

(b) Stock JA held that considering the Reasons for Verdict, it was not demonstrated that the police officers had been disbelieved. In his view, whilst there should be no hard and fast rules, it is very doubtful whether the judge should have admitted the materials in the previous case. The strictly correct step would have been not to admit at all. But having admitted, the judge did not err in permitting the jury to see for themselves the extent to which the officers had been doubted. In the event, the appellant had derived a benefit to which he was not entitled.

(c) Cheung JA dissented. The fundamental difference between his approach and that of the majority is that he considered that the magistrate had disbelieved the police officers in the earlier case. And he held that the judge should have given an unambiguous direction to the jury that the relevance of the materials is that the police officers concerned had been disbelieved and they should assess their credibility in the present case in that light. It was a serious misdirection to ask the jury to consider afresh whether they had been disbelieved by the magistrate.

Leave to appeal

16. On 18 September 2002, the Appeal Committee certified the following points of law of great and general importance and granted leave to appeal.

"1. Where it is alleged that a witness fabricated evidence against the accused, can the court permit to be brought out that that witness's evidence was not accepted in an earlier case in which a comparable allegation had been made against him, or can that be permitted only if it is established that the witness had lied in the earlier case?

2. Where it is alleged that a witness fabricated evidence against the accused, and it is brought out that that witness had lied or that his evidence had not been accepted in an earlier case in which a similar allegation had been made against him, is it permissible to invite the jury to examine and determine whether he had indeed lied or his evidence had indeed not been accepted in the earlier case?"

The points raised can best be dealt with by considering the questions formulated below.

The questions

17. The appeal raises the following situation for consideration.

(a) The credibility of a witness in a criminal case is challenged on the ground of his veracity; and

(b) In a previous criminal case:

(i) That witness had given evidence;

(ii) His evidence and hence his veracity had formed an essential part of the prosecution's case; and

(iii) The defendant had been acquitted.

18. In the above situation, the questions in this appeal can be formulated as follows: (1) Whether and if so, in what circumstances the witness in question can be cross-examined on the acquittal in the previous case? (2) If such cross-examination can be permitted, is the finality rule applicable to answers given on such cross-examination?

19. In this context, the reference to "witness" does not include the defendant and it is unnecessary to consider the position of the defendant in this judgment. In the present case, the witness in question was a police officer. But there is no distinction in principle between a police officer and any other witness, whether giving evidence for the prosecution or the defence.

20. As had been made clear, this appeal is only concerned with a challenge to the credit of a witness in a criminal trial on the ground of veracity (as opposed to other grounds). In short, the challenge is that the witness is lying on oath. It is an attack on his honesty in the witness box.

Approach in principle

21. In the Court of Appeal, all three judges applied the approach laid down in the English decision of R v. Edwards (1991) 93 Cr. App. R. 48. The authorities cited from England and elsewhere are of interest. But it is essential to consider what is the proper approach as a matter of principle to the questions arising in this case. An analysis by reference to the principles of the law of evidence may be of assistance to our criminal courts, both in the conduct of jury trials in the Court of First Instance as well as in trials by professional judges in the lower courts, that is, the District Court and the Magistrates' Courts.

22. In discussing the proper approach as a matter of principle, it is convenient first to set out the relevant general principles and then to apply them to the present questions.

General principles

23. In this context, the relevant general principles are as follows. First, where the veracity of the witness is challenged on cross-examination as to credit, subject to the judge's discretion to disallow improper questions, cross-examination about discreditable acts is widely permitted. See Cross and Tapper on Evidence (9th ed.) 306. Its purpose is of course to show that the witness ought not to be believed on oath.

24. Secondly, the cardinal test of relevance in the law of evidence applies to such cross-examination. The subject matter of the cross-examination must be relevant to the witness's veracity. Relevance is a matter of degree.

25. Thirdly, in applying the test of relevance, the court should in its discretion usually permit questions in cross-examination as to credit if the truth of the imputation conveyed would materially affect the court's opinion as to the witness's veracity on the subject matter of his testimony. Conversely, questions in cross-examination as to credit are usually not permissible if the truth of the imputation conveyed would not have any material impact on such opinion. The imputation may relate to matters which are so remote in time or are of such a kind that the truth of the imputation would not have any material impact on the court's assessment of the witness's veracity. cf. Sankey LJ in Hobbs v. Tinling & Co Ltd [1929] 2 KB 1 at 51. The matters about which the witness is questioned in cross-examination as to credit must relate to his likely standing after cross-examination with the tribunal in question. See R v. Sweet-Escott (1971) 55 Cr. App. R. 316 at 320.

26. Fourthly, as a general rule, answers to questions in cross-examination as to credit on any ground including veracity are final and evidence is not admissible to contradict them. See Harris v. Tippett (1811) 2 Camp 637, 638; 170 ER 1277. This can conveniently be referred to as "the finality rule". The rule is conducive to a fair trial. Its rationale is that, as a matter of commonsense, a criminal trial should be kept within proper limits. The court should focus on the issues in the case. Its attention should not be diverted to collateral issues such as credit, the exploration of which may unnecessarily blur or confuse the real issues in a cloud of detail. Although the rule has sometimes been criticized, it is well-established and necessary. However, the distinction between questions going to the issues in the case and those going to credit is sometimes difficult to draw and in some cases, can be a rather thin one.

27. Fifthly, there are well established exceptions to the finality rule. It is unnecessary to go into them for the purposes of this case. They allow proof by independent evidence of matters which tend to affect the credibility of the witness. As the common law develops in Hong Kong, there may be possible room for relaxation of the finality rule and the list of exceptions is not closed.

Permissibility of cross-examination

28. The two questions raised should be considered separately. Turning to the first question concerning the permissibility of cross-examination as to credit on the ground of veracity by reference to the acquittal in the previous case in the situation in question, the position applying the relevant general principles appears to be as follows.

29. To be permissible, such cross-examination must of course satisfy the test of relevance. It must be relevant to the veracity of the witness. Questions must be of such a nature that the truth of the imputation conveyed would have a material effect on the court's assessment of the witness's veracity.

30. Where in the situation in question, it is sought to cross-examine a witness by reference to an acquittal in a previous case, two main difficulties arise. The first difficulty is the meaning to be attributed to the verdict of acquittal. Although in the situation in question, the prosecution's case in the previous case depended essentially on the evidence of the witness in question, the court would have been bound to acquit unless it was satisfied beyond reasonable doubt on the whole of the evidence that the defendant was guilty of the offence charged. In acquitting, the court may not have found that the witness had lied. Unless in acquitting, the court had found that the witness had lied (or, which amounts to the same thing, the court had disbelieved the witness), the acquittal could not properly be regarded as relevant to the veracity of the witness in the instant case. It would not have a sufficiently material impact on the court's assessment of his veracity.

31. Secondly, even where the acquittal in the previous case involved a finding that the witness in question had lied, that finding may have been in circumstances of such a different kind or may be so remote in time as to render it irrelevant in the instant case. Again, such a previous finding would not have a sufficiently material impact on the court's opinion on his veracity.

32. In principle, in order to satisfy the test of relevance, cross-examination as to credit on the ground of veracity by reference to an acquittal in an earlier case should only be permitted where the following threshold requirements are met: It must clearly be established that: (1) The verdict of acquittal in the previous case involved a finding by the court that the witness in question had lied (or which amounts to the same thing, that the court had disbelieved the witness); and (2) The circumstances of the previous case are of such a kind when compared to those in the instant case and the previous finding is not so remote in time that the finding of lying in the previous case would materially affect the court's assessment of the witness's veracity in the instant case. Unless these requirements are satisfied, cross-examination by reference to the acquittal in the previous case should not be permitted.

33. Whether the first threshold requirement is met depends on an examination of the verdict of acquittal in the context of the issues in the earlier case. A jury verdict would ordinarily be a non-speaking verdict, so that the respective reasons of the several jurors leading to their unanimous or majority verdict cannot be ascertained. The verdict is opaque. That being so, it would only be in very exceptional circumstances that a jury verdict would be able to meet the first requirement; for example, where the jury expresses its view that the witness in question had lied in a rider to its verdict. Similar considerations may apply to a verdict of acquittal given by a judge sitting alone where no reasons or virtually no reasons are given. But where a judge sitting alone acquits and gives reasons, those reasons should be examined in the context of the issues to decide whether a finding was made that the witness in question had lied.

34. As to the second threshold requirement, assuming a previous finding of lying could be established, the circumstances of the previous case must be of such a kind when compared to those in the instant case and the previous finding must not be so remote in time that the previous finding would materially affect the court's assessment of the witness's veracity. Otherwise, the previous finding would not be relevant to the cross-examination as to credit.

35. In coming to a judgment, all the circumstances have to be considered. In considering whether the circumstances are of the kind referred to, all the circumstances of the two cases have to be considered. The circumstances to be examined cannot be exhaustively defined. They may include matters such as the nature and types of offences, the nature of prosecution's case, the modus operandi of the witness, and the allegations made against the witness by the defence. The question of remoteness or proximity in time has to be taken into account.

36. This is an area where it would be unwise to lay down any hard and fast rules. As with many questions regarding relevance, it may sometimes be difficult to draw the line.

Is the finality rule applicable?

37. The second question can now be considered. If the threshold requirements are met, the court should usually in its discretion allow cross-examination by reference to the acquittal in the previous case. It may be that, having regard to the nature of such requirements, where they are met, the prospect of the witness denying that he was found to have lied may be limited in reality. But what if when cross-examined, the witness denies this? Is evidence admissible to contradict his answer?

38. If the finality rule applies, the answer would be no. One is here concerned with cross-examination as to credit and the general rule is that evidence is not admissible to contradict answers given in such cross-examination. None of the well established exceptions to the rule is engaged. However, this would not accord with justice and commonsense. At this stage, the court would already have held in relation to the threshold requirements that the witness was found to have lied in the previous case. Notwithstanding any denial of the previous finding by the witness in the instant case, fairness requires that the finding should be before the court. The court would then have a balanced picture of the witness's credibility and can take the finding into account in assessing his veracity in the instant case. This would involve the admission of evidence to contradict the answer of the witness in the instant case. But the evidence would be limited to proof of the finding. The admission of evidence in these limited circumstances should be regarded as a further exception to the finality rule.

39. This case concerns a verdict of acquittal by a court in a previous case. In principle, a similar approach would apply to a ruling of a court after holding a voir dire.

How the approach would work in practice

40. Having considered the proper approach in principle, it may be of assistance to consider how it would work in practice.

Jury trials

41. The position in jury trials will first be considered. In a jury trial, where counsel for the defendant wishes to cross-examine a witness by reference to an acquittal in a previous case, he should usually seek a ruling from the judge as to whether such cross-examination should be permitted. Obviously, arguments on this matter should take place in the absence of the jury. The materials in the previous case that should be placed before the judge should be as economical as circumstances permit and in any event, should be kept within manageable proportions. In the very exceptional circumstances, where it is suggested that a previous jury verdict amounts to a finding that the witness had lied, the materials would usually consist of the jury's verdict and the judge's summing up or where possible, a statement, agreed for the purposes of the instant case, of the prosecution and defence cases in the previous case. Where the previous case was before a judge sitting alone, the materials would usually consist of the judge's statement of reasons. If they are not self-explanatory, it may need to be supplemented by other materials such as an agreed statement of the kind referred to above.

42. The judge should then consider whether the threshold requirements are met and exercise his discretion accordingly. Where they are met, the judge should usually exercise his discretion in favour of permitting cross-examination.

43. The cross-examination would then be pursued. If the witness agrees that he was found to have lied in the previous case, no question of the admission of evidence to contradict his answer would arise and the jury should then be appropriately directed on the previous finding. But if the witness denies this, then the relevant materials to prove the previous finding could be put in evidence to contradict the answer. The observations made earlier in relation to the materials to be placed before the judge to enable him to consider whether to permit cross-examination would similarly apply to such evidence.

44. Where the witness denies that he was found to have lied in a previous case and evidence is put in to contradict the answer, in directing the jury, the judge should inform them that the evidence has been admitted because the judge is satisfied as a matter of law that the witness was found to have lied in the previous case and that they should proceed on the basis that there was such a previous finding, notwithstanding the witness's denial. This approach is justified since the judge's view that there was such a previous finding is on a matter of law. The jury should not be asked to consider for themselves whether such a previous finding had been made. But the judge should make clear that evaluation of the credit of the witness is a matter for the jury. The judge should direct that they should give the previous finding such weight, if any, as they think fit in assessing the veracity of the witness in the instant case.

Trials before judge sitting alone

45. As to trials before a judge sitting alone, the matter should be dealt with in a similar way with the appropriate modifications.

Other discreditable conduct and other tribunals

46. On the approach laid down above, the threshold requirements include whether the witness in question in the instant case was found by the court to have lied in the previous case. In this appeal, it is unnecessary to deal with other situations. But it should be observed that lying is only one type of discreditable conduct. And there are tribunals which may make findings of lying and other discreditable conduct. Although it is unnecessary to come to any view, it may be that the approach laid down could apply with such modifications as may be appropriate (1) to findings by a court of other types of discreditable conduct of the witness in question provided that the nature of the discreditable conduct is such that the test of relevance is satisfied. An example would be a finding by a court that a police officer had misconducted himself by fabricating a confession. And (2) to findings of lying and other types of discreditable conduct of the nature referred to above by tribunals, other than courts, for example, by disciplinary committees or tribunals.

The authorities

47. A number of authorities were cited in the course of argument. The main English authority is R v. Edwards (1991) 93 Cr. App. R. 48 which dealt with two earlier cases: R v. Thorne (1978) 66 Cr. App. R. 6 and R v. Cooke (1987) 84 Cr. App. R. 286. A number of subsequent cases applying Edwards were cited, such as R v. Guney [1998] 2 Cr. App. R. 242; Persad v. The State (Privy Council) [2001] UKPC 2; R v. Waseem Malik [2000] 2 Cr. App. R. 8. The Court was also referred to Australian and South African authorities on various aspects of the principles in the law of evidence.

48. Edwards has been applied in Hong Kong. See R v. Lam Wai-keung [1994] 2 HKCLR 9. As had been pointed out, the Court of Appeal in the present case applied it.

49. The authorities have been read with respectful care. Bearing in mind the experience of the administration of criminal justice in Hong Kong, the approach as set out in this judgment is considered to be the proper approach. It is unnecessary and it would not be conducive to clarity to embark on an exercise comparing in detail the approach here to that adopted in Edwards and subsequent cases. It is sufficient for the following points to be made.

50. First, where on the proper approach adopted here, cross-examination is permitted, this approach differs from that of Edwards in relation to the admission of evidence, limited to proof of the previous finding that the witness had lied, to contradict answers given in cross-examination. For reasons already explained, this should be permitted as a further exception to the finality rule. In contrast, this was rejected by Edwards which would only allow cross-examination in limited circumstances, but not the admission of evidence to contradict answers given in cross-examination. See Edwards at 59.

51. Secondly, it may be that the second threshold requirement in the approach adopted here, which is considered appropriate as a matter of principle, has not yet received full attention in the English cases.

52. Thirdly, there may well be differences between the approach adopted here and that in the English cases and that the different approaches may well lead to different results in certain cases. That being so, the English cases in these matters should not be regarded as having any precedent value in Hong Kong.

53. Finally, the criminal courts in Hong Kong should apply the approach adopted here in guiding them to make decisions in this area. In applying it, it has to be acknowledged that it may sometimes be difficult to decide on which side of the line the case falls. This is no different from the application of the law of evidence in other areas. The courts would have to approach the matter with practical commonsense.

Application of the proper approach

54. The proper approach must now be applied to the present case. The prosecution's case depended essentially on the evidence of PW1, a police officer. On his evidence, he searched the appellant and found the dangerous drugs in a bag in the pocket of his jeans. The appellant's case was that he was searched by PW1 but no drugs were found on him and that drugs were found by another police officer, PW4, in the bag in question on the front of the taxi but the appellant had nothing to do with it. In the circumstances, PW1's veracity was an essential matter. Should the defence have been allowed to cross-examine PW1 as to credit by reference to the acquittal in the previous case where the prosecution's case also depended essentially on PW1's evidence? If so, it would follow from the proper approach that evidence of the Reasons for Verdict and the Summary of Evidence in the previous case would be admissible to contradict answers given by PW1.

55. The critical question is whether the threshold requirements were met. As regards the first requirement, was it clearly established that PW1, the relevant police officer in the instant case, was found to have lied in the earlier case? Or which amounts to the same thing, did the magistrate in the earlier case disbelieve PW1? This depends on a proper understanding of the magistrate's Reasons for Verdict in the context of the Summary of Evidence. These documents have been set out in full above. One must take the Reasons for Verdict as formulated by the magistrate who is a professional judge. It would not be appropriate to second guess, let alone speculate, whether the magistrate had other unexpressed reasons in mind which laid behind the Verdict and if so, what they were.

56. In his Reasons for Verdict, the magistrate referred first to PW5's evidence and explained why he had reservations about it. He referred to an evasive answer PW5 gave ("he was trying to get away from the question") and said there were also contradictions in various areas in his testimony of which examples were given. In one respect regarding contacts between the police officers and Leung (the defendant in the earlier trial) about Leung acting as a police informer, he said that the possibility that Leung's version "is true and is greater".

57. At this point of his Reasons, the magistrate had not yet referred to PW1's testimony. He then stated that "PW5's statement", presumably his testimony, had an impact on that of PW1. He referred to PW1's testimony that he had never left Leung until he brought Leung to see the duty officer. The magistrate then wondered why if this was the case, PW1 said he had not heard any conversation between PW5 and Leung. The magistrate appeared to have regarded this as an inconsistency between the evidence of PW1 and PW5. This was the only reference made by the magistrate to PW1's testimony. He then referred to Leung's testimony that it was PW5 and PW3 who had intercepted him, and not PW1. He then asked that if PW3 were not playing an important role (which was consistent with Leung's testimony), why Leung had such a deep impression of PW3 and could even identify him in an identification parade a few months later?

58. The magistrate then concluded: "After considering all the testimonies of the prosecution" (which included the evidence of four police officers, PW1, PW3, PW4 and PW5), "I concluded there are some dubious points in the case. Therefore, I'll give this benefit of doubt to [Leung] and [Leung] is not guilty of the charge".

59. Ultimately, the crucial question is whether the magistrate had found that the police witnesses, particularly PW1, had lied. Considering his Reasons for Verdict as a whole in the context of the Summary of Evidence and bearing in mind that the prosecution's evidence depended essentially on PW1's evidence, what the magistrate held was that he had doubts about various points in the prosecution's evidence and accordingly gave Leung the benefit of doubt, as he was bound to do. On his Reasons, he did not find and could not be regarded as finding that PW1 had lied in the witness box. Or which amounts to the same thing, on his Reasons, he did not disbelieve and could not be regarded as having disbelieved PW1.

60. The position is therefore that the first requirement was not satisfied. At the trial, after considering the Reasons for Verdict and the Summary of Evidence, the trial judge should have made a ruling that the defence should not be permitted to cross-examine PW1 by reference to the acquittal in the previous case. That should have been an end of the matter.

61. As the first threshold requirement was not satisfied, it is unnecessary to consider whether the second requirement was met. It should be observed however that it would appear that it was fulfilled in the present case. The circumstances of the previous case were of such a kind when compared to those in the present case, and the previous case was not so remote in time, that if the magistrate had found that PW1 had lied (or which amounts to the same thing had disbelieved him), that finding would materially affect the jury's assessment of his veracity in the present case. As to the circumstances, both cases involved dangerous drugs. On the prosecution's case in both cases, the modus operandi of the police officers was that PW1 found dangerous drugs on the respective defendants when searched and the same four police officers (PW1, PW3, PW4 and PW5) were involved. In both cases, the defence was that no drugs were found on the search of the respective defendants, and that in the course of the events in question, there were conversations when the police officers asked the respective defendants to be a police informer. As to time, the events in the previous case involving PW1 and other police officers and Leung appear to have taken place in October/November before 5 November 1997. The events in the present case involving PW1 and other police officers occurred on 5 October 1997.

Was the defence prejudiced?

62. At the trial, the judge allowed the defence to cross-examine PW1 by reference to the acquittal in the previous case and admitted in evidence, the Reasons for Verdict and the Summary of Evidence. He then directed the jury that they should decide for themselves "to what extent the magistrate disbelieved" the police witness on that previous occasion and "to what extent, if at all, the magistrate's disbelief of the witnesses in that case undermines their credibility in the present case.".

63. The course taken by the judge was erroneous. As held above, he should not have permitted the cross-examination in question. No question of the admission in evidence of the magistrate's Reasons for Verdict and the Summary of Evidence would have arisen. And no direction on the matter would have been necessary.

64. But the judge having taken the wrong course, was the appellant prejudiced as a result? The answer is no. On the judge's direction, the jury would have come to one of two possible views on the previous case: (i) The magistrate did not disbelieve the police witnesses in question; or (ii) The magistrate did disbelieve them. As had been held above, the magistrate did not disbelieve the witnesses in question. (i) would therefore have reflected a correct understanding of the magistrate's Reasons, and the appellant would not be prejudiced. Although (ii) would have reflected a misunderstanding of the magistrate's Reasons, the appellant was not prejudiced either. On (ii), having come to the erroneous view that the magistrate had disbelieved the police witnesses in the previous case, they would have taken this into account in assessing the credibility of the police witnesses, particularly PW1, in the present case. Taking this into account would not have prejudiced the appellant and indeed, may have benefited him.

65. Accordingly, I would dismiss the appeal.

Mr Justice Bokhary PJ:

66. The administration of criminal justice in Hong Kong depends to a large extent on the courts being able to rely on the evidence of officers of law enforcement agencies like the Police Force, the Independent Commission Against Corruption and the Customs and Excise Service. This ability depends, in turn, on the integrity of those officers and on the vigilance of the courts. This vigilance is necessary because, however high a percentage of those officers are trustworthy, there is always the danger of a few who are not. And this vigilance is served by prudent procedures and rules of evidence reinforced by a prudent judicial attitude.

67. Suppose, for example, the circumstances of a case being tried and those of a previous instance or previous instances are so strikingly similar as to suggest a pattern of fabrication by one or more officers involved throughout. If so, the permissibility of cross-examination on, and the admissibility of evidence of, the strikingly similar features would not depend on any previous case having ended in acquittal or, indeed, even on any previous case having been brought to court. But where a defendant's right to point to previous matters is to any extent dependent on a previous acquittal, I think that it becomes particularly difficult to find or fashion an approach free from drawbacks liable to lead sometimes to serious problems in practice. As a human institution, no criminal justice system can be perfect. But it must be manageable, referable to principle, reasonably safe, basically fair and attuned to the social conditions under which it operates. All things considered, I concur in the approach articulated by the Chief Justice.

68. I turn now to how the present appeal ought to be decided upon the application of that approach as I understand it. In the ruling by which he permitted defence counsel to cross-examine PW1 and another police officer about their conduct in the previous case, the trial judge in the present case referred in terms to "the expressed disbelief of the magistrate of their evidence". When the present case reached the Court of Appeal, Stock JA and Cheung JA took diametrically opposite views on how the magistrate's decision ought to be understood. Stock JA understood the magistrate merely to have doubted the police officers' evidence while Cheung JA, like the trial judge, understood the magistrate to have disbelieved their evidence. Stuart-Moore VP's own understanding was that the magistrate had doubted rather than disbelieved the officers' evidence, but he accepted that both of those understandings were open to the jury. For on the question of whether "the evidence of the police officers in the case before the magistrate had been demonstrated to be false", the learned Vice-President said : "Whilst the jury in the present case was entitled to consider whether this is what, effectively, the magistrate's findings may have amounted to, they were equally, in my opinion, entitled to consider whether the witnesses' evidence had simply been doubted which, from the evidence in the North Kowloon case, seems to be indicated." (Italics supplied)

69. In my view, the crucial question is whether the magistrate preferred Leung's evidence to the officers' evidence. Cheung JA said that by preferring Leung's evidence to the officers' evidence, the magistrate must have disbelieved the officers. There was no room for genuine misunderstanding between Leung and the officers. So if the magistrate had indeed preferred Leung's evidence, it necessarily follows that he disbelieved the officers' evidence.

70. By reference to substance, the whole tenor of the magistrate's reasons is of preference for Leung's evidence to the officers' evidence ? in other words, of belief of his evidence and disbelief of theirs. It is true that when the magistrate referred to the possibility of Leung's version being true as "greater", that concerned Leung's unwillingness to be an informer. But such unwillingness was a major point in favour of Leung's credibility. And when the magistrate then turned to PW1 in particular, he made an observation redolent with disbelief of PW1's evidence on an important matter: "As [PW1] said in his testimony, he had never left [Leung] until he brought [Leung] to see the duty officer and handed to him the dangerous drugs. If this is the case, I wonder why he said had not heard any conversation between [PW5] and [Leung]". A man's liberty is at stake, and he is entitled to a full and fair reading of such an observation made from the seat of justice.

71. I feel unable to say that the magistrate only disbelieved some of the police evidence. After all, the officers were working as a team. And the case could hardly have been any simpler. For the crucial issue was, quite simply, whether or not dangerous drugs had really been found on Leung. Indeed no officer's credibility was more in question before the magistrate than that of the very officer's whose credibility is in question in the present case. For he was the officer who asserted that he had found dangerous drugs on Leung ? just as he later asserted that he had found dangerous drugs on the appellant in the present case.

72. As Cheung JA said, the magistrate's use of expressions such as "dubious points" and "giving the benefit of the doubt" to the defendant do not detract from what he i.e. Cheung JA called "the core decision that the police were disbelieved". It follows that the trial judge misdirected the jury when, despite his ruling in which he referred to the magistrate's "expressed disbelief" of the officers' evidence, he told them that they were free to proceed on the basis that the magistrate had not disbelieved the police officers. The misdirection mattered because the trial judge's ruling was correct. In my view, the appeal should be allowed to quash the conviction and set aside the sentence.

Mr Justice Chan PJ:

73. I agree with the judgment of the Chief Justice.

Sir Noel Power NPJ:

74. I agree with the judgment of the Chief Justice.

Sir Gerard Brennan NPJ:

75. I agree with the judgment of the Chief Justice.

Chief Justice Li:

76. The Court by majority (Mr Justice Bokhary PJ dissenting) dismisses the appeal.