HKSAR v. CHEUNG MAN KIT AND OTHERS

HCCC 236/2018

[2019] HKCFI 2860

IN THE HIGH COURT OF THE

HONG KONG SPECIAL ADMINISTRATIVE REGION

COURT OF FIRST INSTANCE

CRIMINAL CASE NO 236 OF 2018

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REASONS FOR DECISION:

EXPERT EVIDENCE

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INTRODUCTION

1.  The prosecution seeks to adduce the evidence of Senior Inspector Lo Kwok Kin.  The prosecution seeks to adduce this evidence on the basis that Senior Inspector Lo is an expert on the conduct of illicit retail operations to sell dangerous drugs and is an expert on the language typically used in such operations. Counsel for the Accused oppose the admissibility of this evidence.

2.  Senior Inspector Lo outlined his experience and qualifications and the expressions of opinion that he proposes to relate to the jury in a witness statement dated 26 June 2019.  There was a previous witness statement by this officer dated 14 March 2018 and which appears in the Committal Bundle (pages 611 – 677).  In the face of objections to the content of the original statement, the witness statement of 26 June 2019 is a substantially re-cast version of the previous statement.

THE OBJECTIONS

3.  Those representing the Accused object to the reception into evidence of the opinion evidence of Senior Inspector Lo.  The grounds of objection are articulated in a written submission by Mr Y M Liu, Barrister at Law who appears for the 2^nd Accused.  That submission was reinforced by oral submissions.  For all practical purposes the application has been conducted by Mr Liu supported by counsel for the other Accused.  The objections are as follows:

(1)  Senior Inspector Lo is not suitably qualified to express opinions on the topics that he proposes to give evidence about;

(2)  the opinions are irrelevant or insufficiently relevant so that there is a substantial risk that the prejudicial effect of the opinions of Senior Inspector Lo will outweigh their probative value;

(3)  there is no demonstrated need for the evidence because the opinions that Senior Inspector Lo proposes to express focus in a substantial degree on communications between a number of persons in Chinese which the jury would have no difficulty in understanding;

(4)  the proposed evidence to be given by Senior Inspector Lo is biased or there is a substantial risk of bias.  This bias, includes but is not limited to, confirmation bias; and

(5)  the statement by Senior Inspector Lo does not articulate how he comes to his conclusions or the factual basis for those conclusions.

The factual evidence upon which Senior Inspector Lo proposes to base his testimony are a series of WhatsApp messages in what is described as a chat room.  The application to exclude the evidence of this officer does not explicitly express any objection to the reception into evidence of the WhatsApp communications themselves.  The objection is to the commentary of the officer on these messages and the opinions that he expresses on the possible business models that those in the illicit drugs trade might adopt in relation to the retail sale of heroin.  The underlying assumption of the objection, which appears to me to be completely misplaced, is that without Senior Inspector Lo to speak to them, the WhatsApp messages which are the factual underpinning for his proposed testimony would simply go away.  While I could see a multitude of presentational challenges that the prosecution may have in putting the WhatsApp messages before the jury, it is by no means impossible to do so.  The reason I mention this issue at this stage is that when counsel for the 2^nd Accused was pressed as to the true nature of his objection to the evidence of Senior Inspector Lo on the basis of relevance,it seemed to me that a problem those representing the Accused with the evidence was not the medium (Senior Inspector Lo) but the message (the WhatsApp messages).

4.  None of the Accused presently on trial are participants in the communications which are the subject of consideration by Senior Inspector Lo.  There are references in the communications to the Accused in this trial and it is said in addition to the objections outlined in the preceding paragraph that what is at risk in this case is the risk of guilt by association.  That is also connected to the contention that the evidence is either irrelevant or insufficiently relevant.

OUTLINE OF THE CASE FOR THE PROSECUTION

5.  The case for the prosecution is that the Accused presently on trial are participants in a conspiracy to traffic in dangerous drugs.  The dangerous drug in question is heroin.  In essence, it is alleged that the Accused in the present trial are each a participant in this conspiracy because they carried out their part in the conspiracy by actually selling the heroin on what might be called a retail basis.  The case for the prosecution is that this conspiracy was a comparatively large-scale operation requiring substantial organisation in terms of supplying the heroin for retail sale and that involved acquiring what appeared to be substantial quantities of heroin; breaking that heroin down into small retail quantities; organising the sellers; collecting the proceeds of the sale and dealing with those proceeds.  As I apprehend the case for the prosecution there was a retail stall located at a place which is an alley near the Sun Hing Building in Portland Street in Mong Kok and there are persons who organised the supply chain packaging and finance and manage the vendors at the stall in Portland Street.  Apart from the obvious illegality of the product and the activity, the prosecution draws a partial analogy between this operation and a legitimate retail store.  Using this manifestly imperfect analogy, with one possible exception—the 1^st Accused — the Accused presently on trial on that analogy are alleged to be basically the shop assistants.  An important component of the WhatsApp evidence is how those engaged in organised and unlawful selling of dangerous drugs organise themselves to attain that end.

6.  The case for the prosecution seeks to connect the Accused presently before the court with the WhatsApp communications in a variety of ways.  In order to understand the connection, it is necessary to understand the substance of the WhatsApp communications in the WhatsApp and the balance of the evidence that the prosecution proposes to adduce.  The persons identified in the chat room are Fong Chi Wai, Kwan On Tik, Andy and Choi Suet Pai. (That it is these people communicating is capable of being proved by other evidence.)  Those three are amongst those who are mentioned in the particulars of the present indictment as co-conspirators.  (Obviously, that is not evidence against the Accused.  That is what is to be proved.)  The communications between these three persons just mentioned, taken as a whole might justify a properly instructed jury concluding that they are running a retail business selling heroin.

7.  In the course of the WhatsApp exchanges that the prosecution intends to prove, there is content which, taken as a whole, a jury could conclude was a reference to the participation in this retail heroin business of each of the Accused.  The bulk of these references which a jury could conclude was a reference to the Accused are in transaction records.  In the communications (which include recordings of oral messages, text messages and visual messages which a jury could infer are transaction records connected with the business), there are references in the WhatsApp communications which a jury could infer are references to the location of the retail stall.

8.  Three of the Accused have also made admissions against interest.  In those admissions, they describe, in various levels of detail, their activities in carrying out the conspiracy.  Of course, that is evidence against only the maker of the admission.  Each admission could be viewed by the jury as the maker participating in a conspiracy to sell drugs.  The balance of the evidence including the WhatsApp communications are devoted to proof that each of the Accused were in a conspiracy and that conspiracy was the one referred to the in the indictment and in the WhatsApp communications.

9.  The case of the prosecution is that these messages which refer to both locality and, in various instances, (possibly) to the Accused should be tied into the observation evidence and the testimony of the undercover officers who made purchases from some of the Accused in the locality.  The eyewitness testimony of PW1 links each of the Accused to the scene at the alley of the Sun Hing Building.  There is other evidence which, taken as a whole, could lead the jury to conclude that each of the Accused was in the conspiracy framed in the indictment.

10.  The proposed evidence that Senior Inspector Lo intends to speak to is communications by persons other than the Accused in the present trial and, on the prosecution case, the best way to express the involvement of these other persons is that they are, in effect, part of the senior management of the illicit retail drug selling operation.  This is set out in more detail under the next topic heading.

11.  Senior Inspector Lo was not involved in the collecting of evidence.  The Senior Inspector will be asked to comment on evidence collected by others.  In other words, the validity of the opinions that are proposed to be articulated depend on the proof of facts by the prosecution from other sources.  This is to be distinguished from experts such as a forensic pathologist in a murder case who actually performs an autopsy and is, to a large extent, a witness of fact as well as expressing opinions on the facts that he observes.  In many cases of this kind, things like tissue samples are actually examined by other persons and the expression of opinion by the forensic pathologist may include work done and evidence prepared by other persons.  That evidence prepared by others would have to be proved in the ordinary way in order that the forensic pathologist might express an opinion on it.

THE PROPOSED EVIDENCE

12.  There are two sources of information which reveal the nature and scope of the evidence that Senior Inspector Lo proposes to give. The first comes from his written statement.  In addition, this officer gave oral evidence on a voir dire to determine the admissibility of his proposed evidence.

13.  The proposed evidence to be given by Senior Inspector Lo is a statement dated 26 June 2019 together with an annex which records communications between persons operating 8 telephone numbers through the well-known communications medium of WhatsApp.  Four of the numbers are used by unknown persons.  The other four are operated by Mr Fong Chi Wai (1 number); Mr Kwan On Tik, Andy (1 number) and Mr Choi Suet Pai (2 numbers).  The evidence is derived from an annex to the witness statement of Senior Inspector Lo which is an extract of the communications through WhatsApp.  The communications involve transcripts of voice communications through WhatsApp; text messages through that medium and pictures sent through that medium.  The annex is, for the most part in Chinese and is yet to be translated.  Once the annex is in proper form it is intended that it go before the jury and that Senior Inspector Lo will comment on aspects of it.

14.  The limitations in my own literacy mean that I cannot read the annex—at present.  It is in the final stages of translation.  However, I asked the Court Interpreter to translate one of the entries which was, it is no understatement, a somewhat more profane version of the brief (and very mild) description of that exchange in the witness statement of Senior Inspector Lo.

15.  What this officer intends to say if he is permitted to testify as an expert is that there are operational models that illicit retail drug selling businesses use and he expresses his opinion on how what he saw and heard in the WhatsApp communications might fit in to such a model.  His statement demonstrates which of these communications he intends to use.  Of course, it would be open to counsel for the Accused to demonstrate how the officer might have been inappropriately selective.

16.  The statement also reveals evidence from Senior Inspector Lo‘s experience as to the jargon that drug traffickers typically use and might use in a drug selling retail operation.  Taken as a whole, his testimony in this regard is that many of the terms used by such persons are words or phrases which are sometimes well-known to the community but are used in different ways to ordinary usage.  He also refers to phrases which are perhaps unique to the illicit drug trade.  An example of drug traffickers using a word in common use in the community is that the slang term commonly used for methamphetamine hydrochloride (I can safely infer that these two words are not in wide use in the drug-trafficking business) which is commonly known as “ice” is referred to in the drug-trafficking trade as “pork”.  Senior Inspector Lo gave numerous other examples.  Cantonese is a changing language.  The officer makes the point that the language of the traffickers changes very rapidly.

17.  In addition, in the course of determining the admissibility of this proposed testimony, the prosecution called Senior Inspector Lo to testify about proposed evidence.  It is no understatement to say that I obtained a much clearer picture of the qualifications and experiences of this officer from his oral testimony.  That is also true in relation to the proposed scope of his testimony if he is permitted to expert evidence.

18.  This officer has been a police officer since June 2005.  He started in a District Special Duties Squad since June 2008 and within a fairly short time in his career moved into a District Intelligence Squad.  By December 2013 he had joined the Intelligence Division of the Narcotics Bureau. He remained in this post until April 2019.  As I understood his evidence, Senior Inspector Lo has some hands-on experience as an investigator but has become more involved in the course of his career with the intelligence side of police work.  Focusing on his work in the Intelligence Division of Narcotics Bureau, he told the court that one of his duties was to analyse information received from informers and informer handlers in the Narcotics Bureau.  He told the court that he was able to access drugs related information that was received from the intelligence units of the Narcotics Bureau and other units in the Hong Kong Police Force.  He also had access to such information from other law enforcement bodies.  He asserted in his testimony that he has become conversant with narcotics prices, types, packing methods, purities, slang, terminology, street nicknames of dangerous drugs and the like which are currently used in the illicit drugs market in Hong Kong.  In addition, he has undertaken what is characterised as the Drugs Expert course held by the Narcotics Bureau and has also attended courses held by the Italian Central Directorate of Anti-Drug Services in Italy.  However, most of his training and learning from which he derives what he says is his expertise comes from on-the-job training.  He told the court that one of the things that he has had to do over the years is to become familiar with the manner in which drug traffickers organise their operations and drug-related jargon.  He told the court that he has come to learn of these matters through:

(1)  speaking directly with informers, arrested persons and prisoners involved in dangerous drug;

(2)  through briefings and meetings with colleagues who speak directly with informers, arrested persons and prisoners involved in dangerous drugs;

(3)  investigating and handling cases relating to dangerous drug; and

(4)  briefings and meetings with colleagues to investigate and handle cases relating to drugs.

Senior Inspector Lo readily accepts that there is no written manual of drugs jargon.

19.  The consideration of the present case by Senior Inspector Lo came about when officers who were investigating that case asked him for his opinion on communications between the users of a vast number of mobile phones seized in this operation.  He testified that he reviewed the information which had been reduced onto a DVD and came to the view that there was potential evidentiary relevance in relation to drug-related criminal activity.  He pointed in particular to a “chat room” which had been set up by certain of the persons said to be in the criminal conspiracy which was the subject of investigation by the officers involved in the present case.  As a result of this Senior Inspector Lo told the court that he asked one of the investigators to reduce that information which has become the annex to which I have already made reference.

20.  What was clear from the testimony of Senior Inspector Lo is that he was not involved in this case other than to review evidence and information derived from other police officers.

21.  A focus of the cross examination of Senior Inspector Lo was to look at the knowledge and experience of Senior Inspector Lo.  It was clear that the vast bulk of his training was on-the-job training together with the two courses already mentioned.  Senior Inspector Lo said that he has made no notes over the years.  He recognised that the jargon has, in some respects changed over the years.  Senior Inspector Lo told the court that he has provided just under 1000 witness statements about various aspects of drug trafficking including estimations of street value of drugs and the explanation of matters such as the jargon used by those involved in the drug trade.  He told the court that he has testified as an expert on between 10 and 15 occasions and, focusing on matters such as jargon, on between three and five occasions.  He believes that his testimony was accepted.

22.  In the course of cross examination by Mr Liu, this officer was closely examined on his experience and activities and the scope to which he was more focused on being an intelligence officer as opposed to a hands-on investigator.  In this regard, Senior Inspector Lo said that he developed information in the course of his duties for the use of other units.

23.  Senior Inspector Lo expanded to some degree on the observations in his witness statements about the set up of illegal drug retail operations.  He indicated that such operations vary in size and the amount of,as it were, specialisation involved was related to the size of the operation.  He himself had been involved in the consideration of retail operations which had three or four stalls.  (This one is alleged to have only one stall.)  He said that for smaller operations, some of the persons involved in those might have multiple duties.

24.  Cross examination then focused on certain examples in the analysis by the Senior Inspector.  There were two principal concerns on this. The first was that he was simply summarising the communications and placing his own gloss on those.  Indeed, the translation of the profanity-‌laced communication in the annex came about as a result of this.  Senior Inspector Lo said that one of the matters which was critical to his analysis was to see the communications in context and in the context of the somewhat specialised language of drug dealers.  The second concern was cross examination about some of the slang terms that the Senior Inspector said were unique to the drug trade.  As pointed out that some of the slang used was perfectly ordinary language and contained no code or concealment in it.  Implicit in the cross examination about that aspect was that ordinary members of the community would be able to read and understand what was being communicated.

25.  Senior Inspector Lo was also cross-examined upon the basis that at various stage he noted that some of the entries in the annex were not the subject of any comment by him.  Implicit in this line of cross-examination is that the jury would be well capable of reading and understanding this without the aid of an expert.

PRINCIPLES

26.  The principles which govern the admissibility of expert evidence are well known.  These principles start with the proposition that witnesses are normally only permitted to relate factual matters devoid of expressions of opinion.  In this regard, expert evidence is an exception to that basic rule. The conditions for admissibility are as follows:

(1)  The evidence must be relevant to a fact in issue in the case.

(2)  The subject matter is some recognised field of science, art or learning which is capable of being made the subject of study, experience or research and in which a person can by study, experience or research become expert or skilled.  In this regard, the field of expertise in question must involve knowledge of matters which are outside the knowledge or experience of ordinary persons and which is sufficiently organised or recognised to be accepted as a reliable body of knowledge or experience.

(3)  The person proposing to give the evidence is sufficiently qualified or expert in his field.

(4)  The area for consideration is one that the tribunal requires the assistance of an expert.

There must be a factual basis for the evidence.  There remains perhaps a further requirement which is basically an application of a more general rule that the court retains a discretion to exclude otherwise admissible evidence of the prejudicial effect of that outweighs the probative value.

27.  These are issues of admissibility.

28.  The first issue is whether the proposed witness is suitably qualified to express opinions about the drugs trade.  In this regard, generally,the considerations are:

(1)  The academic qualifications of the witness—the degrees, diplomas, associateships or certificates held by the expert which are relevant to the topic under consideration.  The time and place at which the qualifications were obtained are also relevant.

(2)  The extent to which the expert has made a special study of his subject and the diligence with which he keeps ‘up-to-date’ with recent developments in the field.

(3)  The practical experience gained by the expert in exercising his knowledge in his special field and the degree of authority and responsibility exercised by the expert in doing so.

(4)  The number of times that the expert has been permitted by other tribunals to give expert evidence on the subject and the extent to which those other tribunals have accepted him as an expert.

(5)  The extent to which the expert has published learned articles or books or other works on the topic.

(6)  The extent to which the expert’s work is subject to peer review.

29.  On-the-job training, the accumulation of experience and knowledge may be the basis of expert opinion.  Examples of this may be seen in cases such as R v Marinovich(1990) 46 A Crim R 282; R v Anderson (1992) 64 A Crim R 312, 326; HKSAR v Ip Tin Wong & Ors [2004] HKCU 466 (unreported, CACC 241/2003, 30 April 2004) and Myers v R [2016] AC 314.

30.  In R v Marinovich, the Court of Appeal for Western Australia considered the admissibility of opinion evidence to explain certain terms used in telephone intercept which were alleged to contain conversations about drug trafficking.  In that case, the Court of Appeal observed:

“ In our opinion the evidence of police officers based on their accumulated experience combining personal observation with information received concerning characteristics, prices, packaging, terminology and availability of heroin by comparison with other illicit drugs was relevant and admissible. Such evidence is in the nature of expert evidence although it may also involve factual evidence of personal experience and observation. Expert evidence about such matters necessarily involves some hearsay evidence. It would be quite artificial and place an unnecessary restraint on prosecution and police work to limit such evidence to those who had been involved in undercover work in the illicit drug market.”

Their Honours went on to make the point that the sources that such officers could use were not limited to personal observation but it was open to them to use informers and intelligence reports.

31.  In HKSAR v Ip Tin Wong & Ors [2004] HKCU 466 (unreported, CACC 241/2003, 30 April 2004), testimony by experts on illicit gambling was admitted.  At trial, these witnesses told the Court that they acquired their knowledge by on-the-job training and were experts in matters such as the methods used by unlawful gamblers in the manner in which they organised their operation.  At trial the experts gave evidence matching betting slips seized by the police and a recording of gambling operations also seized by the police.  The experts also testified as to the commercial or financial aspects of the operation and that included how these bookmaker’s reward was based on a percentage of bets laid.  It is perhaps noteworthy that in the field of illegal gambling, expert evidence is recognised through section 20(3) of the Gambling Ordinance, Cap 148.  Cheung JA, giving the judgment of the Court of Appeal, observed that section 20(3) gave statutory recognition to experts in illicit gambling.  He observed (§48):

“ In this case the knowledge of the operation of bookmaking and the methods used by bookmakers in carrying out the operation are matters which required study or needed to be gained by experience. The opinion given by a witness based on such knowledge clearly falls within the ambit of expert evidence.”

Similarly, in HKSAR v Ng Chi Kin CACC 300/1997 it was recognised that evidence of the ‘street’ value of illicit drugs has been given in Hong Kong courts for a very long time.  That may involve the collation of information from others about the value of seizures of drugs over time.  The use of police officers as expert witnesses in relation to particular types of criminal conduct was again considered in R v Yuen Ying Hung [1993] 2 HKCLR 90, 92 where it was necessary to prove that a sign board could be interpreted as offering prostitution services.  It was held that a police officer who had gained her expertise and knowledge as a result of anti-vice duties could give expert evidence in relation to the sign in its context of what appeared to be sign relating to a one-woman brothel.

32.  It is also instructive to consider Myers v R [2016] AC 314.  This concerned the admissibility of evidence given by persons said to be expert in gangs.  This is relevant to the case for the prosecution which was that the murders (and one attempted murder) in question were all gang-‌related.  Lord Hughes JSC delivering the advice of the Privy Council,held that police officers could give such evidence.  He observed (§57):

“ Police officers have been accepted as expert witnesses in several different contexts and in many common law jurisdictions. A simple example is the police officer who has special training (and considerable experience) in the investigation and reconstruction of road traffic accidents. He may well be as much an expert in his field as any consulting accident engineer, and he is accepted as such routinely in both civil and criminal trials: see for example R v Oakley [1979] RTR 417, 420 where Lord Widgery CJ held in emphatic terms:

‘we would like to make it quite clear straight away that there is no question of a police officer being prevented from giving evidence as an expert if the subject in which he is giving evidence as an expert is a subject in which he has expert knowledge, and if it is restricted and directed to the issues in the case.’

In such a case the expertise in question is as to the behaviour of motor cars, the effects of road surfaces and the like.  In other cases, however, a police officer has been permitted to give expert evidence about criminal behaviour.  An example is evidence of the customary practices of drug users, in relation to such matters as packaging, methods and quantities of usage and supply, and prevailing price: see R v Hodges [2003] 2 Cr App R 15, in which this type of evidence was held admissible.  Evidence of the practices, mores and associations of gangs, whether general or particular, is in a similar category.  It has been received in several jurisdictions and there can in principle be no objection to it being given by a police officer, providing that the ordinary threshold requirements for expertise are established, and providing that the ordinary rules as to the giving of expert evidence are observed.”

The critical passage just cited makes it plain that such an officer, in order to be considered an expert, a police witness must demonstrate the threshold requirements of expertise.

33.  Lord Hughes held that the standards of independence and objectivity applied with equal force to such officers.  He endorsed the set of standards which appear in the well-known case of National Justice Compania Naviera SA v Prudential Assurance Co Ltd (The Ikarian Reefer) [1993] 2 Lloyd’s Rep 68, 81 and noted that they had been summarised in the criminal context in R v Harris [2006] 1 Cr App R 5, §§271 – 272 as follows:

(1)  Expert evidence presented to the court should be and seen to be the independent product of the expert uninfluenced as to form or content by the exigencies of litigation.

(2)  An expert witness should provide independent assistance to the court by way of objective unbiased opinion in relation to matters within his expertise.  An expert witness in the High Court should never assume the role of advocate.

(3)  An expert witness should state the facts or assumptions on which his opinion is based.  He should not omit to consider material facts which detract from his concluded opinions.

(4)  An expert should make it clear when a particular question or issue falls outside his expertise.

(5)  If an expert’s opinion is not properly researched because he considers that insufficient data is available then this must be stated with an indication that the opinion is no more than a provisional one.

(6)  If after exchange of reports, an expert witness changes his view on material matters, such change of view should be communicated to the other side without delay and when appropriate to the court.

34.  Lord Hughes in Myers recognised the challenges which face a police officer giving evidence as an expert but made it plain that the standards are the same for all experts.  He observed (§60):

“ Compliance with these exacting standards can be difficult for a police officer who is effectively combining the duties of active investigator (if not of the current case) with those of independent expert. It is particularly important that such a witness should fully understand that once he is tendered as an expert he is not simply a part of the prosecution team, but has a separate duty to the court to give independent evidence, whichever side it may favour. In particular a police expert needs to be especially conscious of the duty to state fully any material which weighs against any proposition which he is advancing, as well as all the evidence on which he has based that proposition. When considering an application by the Crown to adduce the evidence of a police expert, it is incumbent on the judge to satisfy himself that these duties are recognised, and discharged.”

The last sentence of this passage makes plain what the duty of the court is in this regard.

35.  In the course of rendering the advice of the Judicial Committee, Lord Hughes referred to two decisions of the Canadian Supreme Court with approval.  The first of these is R v Mohan [1994] 2 SCR 9. To say that this is the foundation case on the admissibility of expert evidence in Canadian proceedings is to make something of an understatement.  The judgment of the Supreme Court was delivered by Sopinka J who held that:

“ Admission of expert evidence depends on the application of the following criteria:

(a) relevance;

(b) necessity in assisting the trier of fact;

(c) the absence of any exclusionary rule;

(d) a properly qualified expert.”

The second decision to which Lord Hughes referred was Sekhon v R[2014] 1 SCR 272.  In that case, the accused was charged with trafficking in dangerous drugs.  He was alleged to be the courier of a very large quantity of cocaine.  That cocaine was found in the vehicle of the accused.  The issue in the case was whether the accused knew that the drug the subject of the charge was in his vehicle.  In the course of his trial, a police expert was called and included in his testimony was his observation that over many years of experience in investigating such cases he did not personally encounter a blind courier over the course of his investigations.  Of this the Supreme Court observed (§49):

“ The fact that Sgt. Arsenault did not personally encounter a blind courier over the course of his investigations is neither relevant nor necessary, within the meaning ascribed to those terms by this Court in Mohan, to the issue facing the trial judge‌—‌namely, whether Mr. Sekhon himself had knowledge of the drugs. The Impugned Testimony, though perhaps logically relevant, was not legally relevant because the guilt or innocence of accused persons that Sgt. Arsenault had encountered in the past is legally irrelevant to the guilt or innocence of Mr. Sekhon.”

36.  Earlier in the judgment in Sekhon v R, Moldaver J considered the principles in Mohan (above) and observed (§46):

“ Given the concerns about the impact expert evidence can have on a trial—including the possibility that experts may usurp the role of the trier of fact—trial judges must be vigilant in monitoring and enforcing the proper scope of expert evidence. While these concerns are perhaps more pronounced in jury trials,all trial judges—including those in judge-alone trials—have an ongoing duty to ensure that expert evidence remains within its proper scope. It is not enough to simply consider the Mohan criteria at the outset of the expert’s testimony and make an initial ruling as to the admissibility of the evidence. The trial judge must do his or her best to ensure that, throughout the expert’s testimony, the testimony remains within the proper boundaries of expert evidence. As noted by Doherty J.A. in R. v. Abbey, 2009 ONCA 624, 97 O.R. (3d) 330, at para. 62:

      The admissibility inquiry is not conducted in a vacuum.  Before deciding admissibility, a trial judge must determine the nature and scope of the proposed expert evidence.  In doing so, the trial judge sets not only the boundaries of the proposed expert evidence but also, if necessary, the language in which the expert’s opinion may be proffered so as to minimize any potential harm to the trial process.  A cautious delineation of the scope of the proposed expert evidence and strict adherence to those boundaries, if the evidence is admitted, are essential.  The case law demonstrates that overreaching by expert witnesses is probably the most common fault leading to reversals on appeal ....  [Emphasis added; citations omitted.]”

37.  What can be derived from Sekhon v R (above) is that it is plain that critical to the duties of the trial judge is a requirement to carefully analyse the evidence to take account the benefits which may accrue from the reception into evidence of expert opinion and weighed against the possible costs to the integrity of the trial process.

38.  The reference in Sekon to R v Abbey is of importance because this case came before the Ontario Court of Appeal many years later following the second retrial which arose out of that case.  In that case, the accused was charged with murder.  The impugned expert evidence was the significance of a tattoo on the body of the accused.  The prosecution relied on the person who was said to be an expert on gang culture.  He testified that a teardrop tattoo meant one of three things: the wearer of the tattoo had lost a loved one or a fellow gang member; the wearer had spent “hard” time in prison; or the wearer had murdered a rival gang member.  Then, [the expert] buttressed his opinion with a powerful set of statistics, which were drawn from six studies he authored between 1995 and 2005, and which the Crown relied on to argue Abbey had obtained a teardrop tattoo to signify he had killed a rival gang member.  In giving the judgment of the Ontario Court of Appeal in R v Abbey [2017] ONCA 640, 350 CCC (3d) 102, Laskin JA considered the framework in which the admissibility of expert evidence should be considered.  Following a slightly complex analysis,the upshot of that was that the test now approved by the Canadian Supreme Court is (§48):

“ Expert evidence is admissible when:

(1) It meets the threshold requirements of admissibility, which are:

a. The evidence must be logically relevant;

b. The evidence must be necessary to assist the trier of fact;

c. The evidence must not be subject to any other exclusionary rule;

d. The expert must be properly qualified, which includes the requirement that the expert be willing and able to fulfil the expert’s duty to the court to provide evidence that is:

i. Impartial,

ii. Independent, and

iii. Unbiased.

e. For opinions based on novel or contested science or science used for a novel purpose, the underlying science must be reliable for that purpose,

and

(2) The trial judge, in a gatekeeper role, determines that the benefits of admitting the evidence outweigh its potential risks,considering such factors as:

a. Legal relevance,

b. Necessity,

c. Reliability, and

d. Absence of bias.

[49] In short, if the proposed expert evidence does not meet the threshold requirements for admissibility it is excluded.  If it does meet the threshold requirements, the trial judge then has a gatekeeper function.  The trial judge must be satisfied that the benefits of admitting the evidence outweigh the costs of its admission.  If the trial judge is so satisfied then the expert evidence may be admitted; if the trial judge is not so satisfied the evidence will be excluded even though it has met the threshold requirements.”

The reference to the role of the judge as “gatekeeper” is derived from an earlier decision of the Canadian Supreme Court in R v J-LJ [2000] 2 SCR 600.

39.  In the present case, counsel for the 2^nd Accused argues that the proposed expert opinion is not relevant or sufficiently relevant and that it is not necessary because the jury could readily understand the structure of the enterprise without the assistance of Senior Inspector Lo.  There is also an argument that the effect of the evidence is to create an air of guilt by association in that in the communications there is reference to a name which the jury might infer was the name of the 2^nd Accused.  I mention that at this stage for completeness because that reference is not the product of expert opinion and is in the communications and would be there regardless of whether or not the officer was permitted to give expert evidence.

40.  The principles governing the issue of whether the evidence is necessary are expressed throughout the common law world in the same way. The principles derive from the observations of Lawton LJ in R v Turner [1975] QB 834.  The essence of the principal is that there must be a demonstrated need for assistance from the expert.  The purpose of calling an expert is to supplement the knowledge of the court or give the court access to fields of knowledge that it would otherwise not possess so as to help it understand the evidence.

41.  In determining whether the evidence is relevant, it is necessary to fully appreciate the case of the prosecution and where the intended evidence fits into that case.  In other words, relevance is highly context- specific.  However, in Mohan (above), the Supreme Court of Canada observed in relation to the issue of relevance:

“ Relevance is a threshold requirement for the admission of expert evidence as with all other evidence. Relevance is a matter to be decided by a judge as question of law. Although prima facie admissible if so related to a fact in issue that it tends to establish it, that does not end the inquiry. This merely determines the logical relevance of the evidence. Other considerations enter into the decision as to admissibility. This further inquiry may be described as a cost benefit analysis, that is ‘whether its value is worth what it costs.’ See McCormick on Evidence (3rd ed. 1984), at p. 544. Cost in this context is not used in its traditional economic sense but rather in terms of its impact on the trial process. Evidence that is otherwise logically relevant may be excluded on this basis, if its probative value is overborne by its prejudicial effect, if it involves an inordinate amount of time which is not commensurate with its value or if it is misleading in the sense that its effect on the trier of fact, particularly a jury, is out of proportion to its reliability. ...

      There is a danger that expert evidence will be misused and will distort the fact-finding process.  Dressed up in scientific language which the jury does not easily understand and submitted through a witness of impressive antecedents, this evidence is apt to be accepted by the jury as being virtually infallible and as having more weight than it deserves.”

42.  The authorities demonstrate that an expert may only be permitted to testify to matters within his own specialist knowledge gained through qualifications, study and experience: Dasreef Pty Ltd v Hawchar (2011) 243 CLR 588.  (Dasreef was followed by the Court of Final Appeal in Fu Kor Kuen Patrick & Anor v HKSAR (2012) 15 HKCFAR 524 (FACC 4/2011, 24 May 2012), §48.)  This has two components.  The first is that the expert should as a threshold requirement demonstrate in his report that the opinions expressed therein are the product of his expertise.  In Dasreef, the High Court of Australia held that (§42) “A failure to demonstrate that an opinion expressed by a witness is based on the witness’s specialised knowledge based on training, study or experience is a matter that goes to the admissibility of the evidence, not its weight.”  The second component ofthis is that the opinions expressed in the report of the expert and, if admitted,in the testimony of the expert must be within the boundaries of the expertise of the witness.  This was demonstrated in Fu Kor Kuen Patrick & Anor v HKSAR where Gleeson NPJ made the point (§§47 – 48) that the experts under scrutiny in that case were highly qualified and well capable of expressing opinions within their expertise but that this did not give the experts license to roam over fields outside their expertise (in that case the state of mind of the accused) simply because they were expert in something.  Both of the components of this rule require analysis in determining the admissibility of the proposed evidence and a supervisory role if the expert is permitted to testify to matters within the expertise of that witness.

43.  The combined effect of these authorities imposes on the court an exacting standard of admissibility.  Even if the impugned expert evidence is admitted, the authorities plainly impose on the court an obligation of monitoring that evidence to ensure that these standards are adhered to throughout the presentation of the evidence.  That, of course, requires the vigilant participation of counsel for the parties on both sides.  I add emphasis to the word “both” in the previous sentence because it would be wholly inappropriate for counsel on one side or the other side on his or her hands when the witness strays into areas which are or possibly are outside the expertise of that witness.  After all, in the adversarial system which underpins criminal trials, it is counsel for one or other of the parties who knows best interest of his or her client and whether the expert has overstepped the boundaries of their expertise in a manner which adversely affects the interest of that party.  Although not part of the authorities already discussed, it must also be true that where such evidence is admitted, there is an obligation imposed on the court in summing up the case to the jury to ensure that the expert evidence is placed in its proper context.

EVALUATION

Senior Inspector Lo is a witness of truth

44.  In my opinion, when Senior Inspector Lo gave evidence before this court, he was a witness of truth.  In many ways, that is not the issue and nothing in the careful cross examination by Mr Liu ever suggested that the officer was not a witness of truth.

Evaluation of qualifications and experience

45.  Senior Inspector Lo has built up a substantial record of experience in intelligence matters relating to the operation of the police.  Although it does not appear that his experience in this regard is uniquely connected with intelligence concerning illicit drug trafficking, it is plain to me that a substantial part of his experience is in that field.  Not only that, as I have already outlined, in recent years he has been in the Intelligence Division of the Narcotics Bureau.  (He has moved on from there recently but that does not diminish the position.)

46.  I am entirely satisfied that this officer has, over the years, built up a substantial body of knowledge and experience in matters relating to the illicit drug trade.  I am satisfied that the vast majority of his knowledge and experience is derived from what he has learned from day-to-day work.  He has clearly derived some of his knowledge from the investigations and enquiries of others but I am satisfied that he is sufficiently knowledgeable and experienced to be able to properly evaluate the information he receives from others.  His knowledge and experience have accumulated over a substantial number of years.  I am not able to say with certainty at what stage of his career Senior Inspector Lo could be characterised as an expert in　matters relating to the illicit drug trade but I am wholly satisfied that he is now　so knowledgeable that he could be characterised as an expert on this topic.

47.  Senior Inspector Lo demonstrated, particularly through his oral testimony, that he is a responsible officer.  This is important because the declarations of his understanding of his responsibility to the court when assuming the role of expert witness must be more than the mere mouthing of the usual words that one sees in either expert reports or, in this case the witness statement of this officer.  He presented in such a way that I am satisfied that he takes seriously these obligations.  Senior Inspector Lo presented as a serious minded and un-dogmatic person.  I mention this aspect of his testimony because on the Canadian authorities which, as I have indicated, I consider to be a cogently reasoned method of analysing the admissibility of expert evidence, how the officer is likely to present is one aspect of the risk analysis that the Canadian methodology suggests that the Court undertake.  An example at the other end of the spectrum might be seen in relation to one of the pathologists who testified in R v B [2006] EWCA (Crim) 417, [2006] 2 Cr App R 3 who appears to have been characterised as somewhat dogmatic in her presentation.  While that would be unlikely to disqualify such an expert, (and did not disqualify the expert in R v B) it is an issue to be considered and may well be slightly higher up the list of concerns where, as here, the knowledge of the expert is very much based on on-the-job training and experience.

Demonstrated connection between expertise and opinions expressed

48.  The court is also required to consider whether the opinions proposed to be expressed by Senior Inspector Lo are the product of his qualifications and training.  In my judgement, the witness statement amply demonstrates that.  Further, I do not detect any expression of opinion which is outside the boundaries of his expertise or threatens those boundaries.  The officer asserts a knowledge based on accumulated experience and it appears to me that his opinions about the possible business models used by illicit drug traffickers is well within the scope of that expertise.  The same applies to his discussion of the language employed by such persons.  His selection of particular communications in the WhatsApp messages does not suggest to me that those selections are due to improper selectivity.  It is perhaps appropriate to make it plain that the testimony of this officer does not in any way directly link the Accused with the conspiracy.  If that is to be proved it must be done by other evidence.  However, that said, plainly that proposed evidence of Senior Inspector Lo does provide a framework of analysis as to that issue which is capable of being accepted by the jury.

49.  Nothing in the proposed testimony raises red flags that suggest　that the proposed testimony of Senior Inspector Lo is likely to range outside the boundaries of his expertise.  As I have already mentioned, no doubt if that occurs to the detriment of the interest of the Accused, their counsel will　be vigilant and raise the matter with the court.  While obviously the problems　identified in Fu Kor Kuen Patrick & Anor v HKSAR (above) is but an example of where the boundaries of expert evidence are either threatened or actually breached that case serves to remind concerned that there are boundaries.

Relevance

50.  In my judgement, the evidence is logically relevant to the issues in the case.  The case for the prosecution is that the Accused are part of a criminal conspiracy to traffic in dangerous drugs which is substantially wider than the mere peddling of a few pellets of heroin in a back alley of Portland Street.  Evidence of how the criminal enterprise might be organised both in terms of the supply of product and the administration of the enterprise including staffing and financial aspects are likely to greatly assist the jury.  While the enterprise may have some analogies with an ordinary retail operation which is thoroughly legitimate, the fact that the unlawful storage, supply and sale of heroin is a thoroughly illegitimate operation is a matter of clear relevance.  The employment of lookouts, the mode of packaging and the mode of selling together with the disposition of the proceeds are wholly unlike legitimate retail operations.

Necessity

51.  I am also firmly of the view that the necessity for this evidence is clearly demonstrated in the sense that this is almost certainly entirely outside the knowledge of jurors.  To the extent that there is an analogy between this operation and a legitimate retail operation, that is not so. However, as I have already pointed out, there are important aspects of this operation which would be outside the knowledge of a juror.  Those aspects concerned the illicit component of the operation.  The fact that there are aspects of the enterprise which might be within the knowledge of jurors is not the point.

52.  As I have already noted, the evidence which underlies the opinions of Senior Inspector Lo is independent from him and would have to be proved in the ordinary way.  In this context, the jury’s evaluation of the opinions of this officer would be conditional on those facts being proved to their satisfaction.

Bias

53.  The effect of this argument is twofold.  The first is that Senior Inspector Lo likely to give highly biased evidence which the jury have no way of cross-checking.  This is particularly exacerbated, so the argument runs, by the fact that this potential witness is a serving member of the Hong Kong Police Force which is a disciplined service and his first loyalty might lie with the Force as opposed to carrying out his obligations to the Court.  I have already made observations on aspects of this earlier in this ruling.  In addition to those observations, in my judgement, this aspect of the argument substantially undervalues the commonsense and knowledge of the world that a jury invariably possesses.  It also undervalues the effect of cross examination and directions that the jury would receive in the event that the evidence was received into evidence.  In my judgement, the jury are perfectly capable of evaluating the proposed testimony, particularly against the background of cross examination and directions which the jury will receive.

54.  The second argument is that there is likely to be an element of what is sometimes called confirmation bias in the proposed testimony of Senior Inspector Lo.  Confirmation bias is the tendency to search for, interpret, favor, and recall information in a way that confirms one’s pre­existing beliefs or hypotheses.  In this case, the facts of the case are proved independently of the testimony Senior Inspector Lo.  Indeed, if it is not proved independently then the officer’s testimony is valueless.  Part of the testimony of the Senior Inspector deals with the possible models of illicit narcotics retailing.  He looks at the WhatsApp communications against that background.  It is conceivable that there is confirmation bias in the descriptions by the Senior Inspector of these models and his treatment of the communications.  I rate the level of danger as low.  This argument also ignores the common sense of juries against the background of potential of cross examination and proper directions in the summing-up.

55.  In my judgement, there is nothing in either of these two arguments which causes me to exclude the proposed evidence.

Risk evaluation

56.  There is always the risk, as the authorities recognise, of the jurors either being overawed or possibly misusing the expert evidence of Senior Inspector Lo.  I have already adverted to my evaluation of Senior Inspector Lo as a witness and I think the risk deriving from his conduct of either of these two things is low.  There is the risk that the jury may consider that his expert evidence is the final word on the topic and that this may adversely impact the fundamental rule that the jury are the final and ultimate evaluators of the facts of the case.  The jury will be instructed in accordance with the Specimen Directions so far as this is concerned.  As presently advised, it will be necessary to reinforce those directions to ensure that the jury appreciate their role as evaluators and that they appreciate the clear boundaries within which this officer will give his expert opinion.  Plainly, the jury will be firmly told that even if they were to accept as correct and valid every word that Senior Inspector Lo is likely to say (which is of course an issue entirely for them), it would still be necessary to consider whether any or all of the Accused joined in the illicit drug-selling enterprise for which the prosecution contends.  In my judgement, at the heart of what this officer proposes to say is to provide what the jury may think is a sensible and cogent framework of analysis.  That is the potential benefit to the case.  In my judgement that far outweighs the risks identified by the authorities.

Prejudice

57.  As I have already identified, a good deal of the sting of the evidence that Senior Inspector Lo proposes to give comes from the WhatsApp communications themselves and not from the officer.  The officer does not express an opinion on whether or not any particular Accused is a part of the enterprise.  The evidentiary basis for that comes from the WhatsApp communications themselves taken together with the balance of the prosecution case.  For example, in those communications there are references to personalities which the jury could infer are references to one or more of the Accused on trial.  Those references would be there regardless　of whether or not Senior Inspector Lo was permitted to give evidence.  This is bound up with whether or not the conduct of each individual Accused could be viewed as an act in furtherance of the conspiracy.  The basic rule is that the out of court acts and declarations of a party to a conspiracy or joint enterprise in furtherance of that conspiracy or joint enterprise are capable of being admissible against the person who made it and the other members of the joint enterprise.  In order for evidence of acts and declarations in furtherance of the conspiracy or joint enterprise to be admissible against a person other than the person who did the act or made the declaration, there must be reasonable independent evidence that the latter was a party to a conspiracy or joint enterprise.  The principles concerning this rule were recently authoritatively articulated in Vivien Fan v HKSAR (2011) 14 HKCFAR 641.  Whether the threshold for the reception into evidence of potential the acts and declarations of any individual Accused is met is entirely outside the scope of the objection and falls for consideration after, if necessary, full argument.

58.  It seems to me that in reality this is all or at least the major part of the point being made by counsel for the 2^nd Accused about guilt by association. It seems to me that this argument confuses the WhatsApp communications with the proposed expert evidence of Senior Inspector Lo.  Even if I held that the officer was not permitted to give expert evidence, it would be perfectly open to the prosecution to seek to present the WhatsApp communications.

CONCLUSION

59.  In my judgement, the proposed evidence of Senior Inspector Lo　meets the stringent criteria for the admissibility of expert opinion.  It remains necessary for the Court, with the assistance of counsel for the parties, to be vigilant to ensure that the concerns outlined in the authorities are observed in the course of this officer testifying.  As I have already observed, much of the effective enforcement of these concerns lies in the hands of counsel for the Accused.