HKSAR v. Un Mark William

HCCC 10/2015

IN THE HIGH COURT OF THE

HONG KONG SPECIAL ADMINISTRATIVE REGION

COURT OF FIRST INSTANCE

CRIMINAL CASE NO 10 OF 2015

(ARISING FROM TWCC NO 1776 OF 2014)

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RULING ON ADMISSIBILITY OF EXPERT EVIDENCE

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Introduction

1.The defence wishes to adduce at trial psychiatric and related evidence in relation to the defendant, consisting of a psychiatric report and two letters from the defendant’s sisters. 

2.Dr LAM Chi Leung, a specialist psychiatrist, has made a report dated 11 December 2015 and a supplementary report dated 7 January 2016, in which he addresses the mental health of the defendant and concludes that he is suffering from schizophrenia with symptoms including grandiose and persecutory delusions, impaired logic of thoughts with disorganized ideas and social isolation. 

3.Whilst the defendant was on remand before being granted bail, he was detained at Siu Lam Psychiatric Centre from 31 July 2014 to 12 August 2014 and from 7 October 2014 to 31 January 2015 for psychiatric assessment and management.  It would appear that the Government psychiatrist, Dr LUI Sing-heung, in his notes dated 29 January 2015 diagnosed the defendant as suffering from chronic schizophrenia and delusional disorder. 

4.I had been previously informed by Mr James McGowan, counsel on fiat for the prosecution, that Dr LUI was not available to provide a report and arrangements would be made for another Government psychiatrist to provide a psychiatric report on the defendant.  Even though the prosecution were on notice to ensure this was done before the trial fixed to commence on 18 January 2016, a report was submitted only by way of memorandum dated 13 January 2016 from Dr Dorothy Tang.  Dr Tang provided a brief summary of Dr LUI’s notes and recorded his diagnosis that the defendant was suffering from a mental illness, namely chronic schizophrenia/delusional disorder.  She recommended that the defendant be remanded to Siu Lam Psychiatric Centre for a thorough psychiatric assessment. 

5.The position taken by the prosecution was to initially object to the admissibility of any psychiatric evidence in relation to the defendant.  A brief written submission dated 15 January 2016 was filed with the Court where objection was taken to the admissibility of the psychiatric evidence on the ground of relevance.  Broad argument was presented on whether such expert evidence was necessary to address issues of fact.  However, in the course of discussion of the prosecution’s submission, the objection was withdrawn when it was acknowledged that the defendant’s mental state, in particular his suffering with a delusional disorder, would be a relevant matter for the jury to have before them when addressing the issue of the defendant’s state of mind at the time of the offence as to whether he knew he was in possession of drugs. 

6.I am satisfied that the psychiatric evidence submitted by the defence in relation to the defendant’s mental illness is a relevant matter that should properly be put before the jury on the issue of the defendant’s state of mind and knowledge.  I therefore rule that the psychiatric evidence sought to be adduced by the defence is admissible. 

7.As a result of the change of position by the prosecution, I was informed that they wished to have the defendant psychiatrically evaluated as suggested by Dr Tang.  However, this requires the defendant being an inpatient at Siu Lam Psychiatric Centre but he has refused to participate in a psychiatric evaluation on this basis.  The prosecution suggested alternative arrangements for the defendant to be psychiatrically evaluated as an outpatient by a psychiatrist appointed by them.  Mr Michael Arthur, counsel for the defendant, did not object to the evaluation taking place by a Government appointed psychiatrist as he may want to rely on the report in light of Dr LUI’s diagnosis.  Mr McGowan quite rightly acknowledged that the prosecution would need to consider the report once it is to hand and assess whether it would have any bearing on the prosecution case. 

8.On 20 January 2016, the issue concerning Dr LUI’s availability was discussed.  Dr LUI appears to have been the treating psychiatrist of the defendant whilst he was at Siu Lam Psychiatric Centre.  From the medical records he has concluded that the defendant suffers from a mental illness, namely schizophrenia or delusional disorder.  In the circumstances, it would be preferable that in light of Dr LUI’s opinion that he provide a full report.  

9.As the trial of the defendant has to be adjourned in order for the prosecution to psychiatrically evaluate the defendant, I requested that inquiries be made as to the availability of Dr LUI at some later date.  I was informed that he was on leave and would not be available until April 2016.  I have now been informed that he is on pre-retirement leave but may be available to provide a report. 

Admitting expert evidence

10.I should make a few comments about expert evidence.  The key considerations for admission of expert evidence are that the subject upon which the witness proposes to give evidence is a relevant matter in the proceedings; the subject is a matter of art, science, learning or knowledge which can become the subject of expertise by study; the witness is proved or admitted to be an expert on the subject; and the subject is one upon which the court requires the assistance of an expert.

11.It is generally understood that expert opinion evidence may only be received on a subject calling for expertise which the court could not be expected to possess, to a degree sufficient to understand the evidence given in the case unaided.  If the court can form its own opinion without the assistance of an expert, the matter being within its own experience and knowledge, expert opinion evidence is inadmissible because it is unnecessary.  See R v Turner [1975] QB 834 per Lawton LJ at 841, applied in R v Loughran [1999] Crim LR 404.

12.Whether a witness is competent to give evidence as an expert is for the court to determine. In R v Bonython (1984) 38 SASR 45, King CJ, explained that the court should approach the issue by addressing the following questions.

“Before admitting the opinion of a witness into evidence as expert testimony, the judge must consider and decide two questions. The first is whether the subject matter of the opinion falls within the class of subjects upon which expert testimony is permissible. This first question may be divided into two parts: (a) whether the subject matter of the opinion is such that a person without instruction or experience in the area of knowledge or human experience would be able to form a sound judgment on the matter without the assistance of witnesses possessing special knowledge or experience in the area, and (b) whether the subject matter of the opinion forms part of a body of knowledge or experience which is sufficiently organized or recognized to be accepted as a reliable body of knowledge or experience, a special acquaintance with which by the witness would render his opinion of assistance to the court. The second question is whether the witness has acquired by study or experience sufficient knowledge of the subject to render his opinion of value in resolving the issues before the court.”

13.As a general proposition, it is not permissible to adduce expert evidence which purports to answer the question for which it is for the court to determine.  This is not so much a prohibition on expert evidence regarding the ultimate issue but recognition of the rule against allowing an expert to testify as to a matter that the court is perfectly capable of deciding.  In this respect, an expert should not usurp the function of the court given that the purpose of expert evidence is to explain to the court matters which it needs to understand, but cannot without expert assistance, as special knowledge or experience not possessed by the court is required in order to reach a just conclusion of the matter it is adjudicating upon. 

14.There are some subjects upon which the court is generally incapable of forming an opinion unassisted, and others upon which it could come to an independent conclusion, but the assistance of an expert would be useful.  The need for expert evidence will very much depend upon the subject matter and the issues and circumstances of the case.  The basic principle is that expert evidence is admissible when it can assist the court. 

15.The fundamental principles to bear in mind on the question of admissibility of expert opinion evidence in criminal proceedings is that, first, it is relevant to a matter in issue in the proceedings, secondly, it is needed to provide the court with information likely to be outside the court’s own knowledge and experience and thirdly, the witness is competent to give that opinion.  Whilst there are other principles relevant to the assessment of expert opinion evidence, it is important to bear in mind that such evidence is within the expertise of the expert and is confined to opinion on the matter in issue requiring expert opinion.  I mention this important principle because Dr Lam in paragraph 6 of his supplemental report addresses issues of fact which are within the domain of the jury as judges of fact in a criminal trial.  Mr Arthur has acknowledged that paragraph 6 addresses factual matters and is outside the expertise of Dr Lam.  So it is therefore important to bear this matter in mind when expert opinion evidence is presented during the course of this trial.

16.With the foregoing principles in mind, I rule that the expert opinion evidence is relevant and admissible as it concerns the defendant’s mental state insofar as he suffers with schizophrenia and delusional disorder.  It follows that the evidence of the defendant’s sisters is also relevant and admissible insofar as it concerns his past conduct and behaviour that reflects on his mental capacity and condition.

17.Mr McGowan has agreed to admit the statements of the defendant’s sisters under section 65B of the Criminal Procedure Ordinance, Cap 221, as long as the statements comply with the requirements of the section and concern instances or events relating to the defendant’s mental capacity and condition.  At this stage, there is no need for me to say any more about the statements of the defendant’s sisters as this is a matter that has been discussed and resolved between counsel.

Mr James McGowan, counsel on fiat, instructed by Department of Justice, for HKSAR

Mr Michael JB Arthur, instructed by Morley Chow Seto, assigned by Director of Legal Aid, for the defendant