HKSAR v. NG CHUN FAI

DCCC 362/2011

IN THE DISTRICT COURT OF THE

HONG KONG SPECIAL ADMINISTRATIVE REGION

CRIMINAL CASE NO. 362 OF 2011

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REASONS FOR VERDICT

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1.  The defendant herein faces a charge of burglary, contrary to section 11(1)(b) and (4) of the Theft Ordinance, Cap 210. He denied the charge of burglary.

2.  There were five prosecution witnesses.  At the conclusion of the Prosecution case, Mr Percy for the defendant made a submission of no case to answer on the charge.  After hearing submissions from him and from prosecution counsel, I found that there was a case to answer.  Having had his rights explained to him by counsel, the defendant elected not to give evidence but called one defence witness.  At the conclusion of the evidence, I heard closing submissions from counsel, and adjourned the matter until today for verdict.

3.  I bore in mind at all times that the burden of proof remained throughout upon the prosecution to prove guilt beyond all reasonable doubt.  The defendant elected not to give evidence.  That was his right and I drew no adverse inference against him for exercising that right. 

4.  I do not intend to repeat all the evidence that was adduced.  Suffice to say that I have considered all the evidence adduced before me as well as the submissions of counsel. It was not disputed that the premises in question were burgled at the material time.  The only issue is whether the prosecution has proved to the requisite standard that the defendant was one of the burglars of the premises at the material time.

5.  Facts admitted by the defendant under section 65C of the Criminal Procedure Ordinance, Cap 221, marked as exhibit P8, disclosed that:

(a) At the material time in 2003, Fu Hua Chemical Industrial Ltd (hereinafter referred to as ‘Fu Hua’) was located at Unit 5, 16^th floor, Millenium Trade Centre, No 56 Kwai Cheong Road, Kwai Chung. This was an office and not open to the public.

(b) At around 1930 hours on 26 February 2003, a staff member of Fu Hua, Ms Yammie Lam Yin-fong, left the office – she was the last member of staff to leave the office, and secured the office when she left. The next day, 27 February 2003, another staff member, Ms Lo Wun Kwai, was the first one to come to work. She noticed that the lock of the front door of the premises had been prized, the premises had been ransacked, and the drawers prized open. She noticed two empty bottles of distilled water, one on an unoccupied desk and one on the boss’s desk. Neither bottle had been on the respective desks before the burglary. Ms Lo recognized the brand of the distilled water, namely ‘Sun ray Cave’, to be the same brand as that of the distilled water she bought for the company, which were stored in the company’s refrigerator in the premises. Photographs were taken of the premises depicting their condition, and these were produced by agreement and marked exhibit P7(1) to (9). The two empty distilled water bottles can be seen in photos 7 and 8, and the refrigerator where similar distilled water bottles were stored can be seen in photo 9.

(c) On 27 February 2003, PC 51211, PW4 in these proceedings, lifted DNA samples from the mouths of the two empty distilled water bottles, which he labeled ‘A’ and ‘B’, and these were subsequently labelled as GPL 4604 and GPL 4605 respectively. The bottle relevant to these proceedings from which a DNA sample was lifted from the mouth is Bottle A, and the DNA sample was labeled with the laboratory reference GPL 4604. On 10 March 2003, DSPC 47123 signed and collected the said DNA samples and delivered them to the Government Laboratory for analysis. The said DNA samples were examined by forensic scientist Lai Kam Ming, PW2 in these proceedings. The chain of evidence in respect of the DNA samples after DSPC 47123 signed, collected and delivered the said DNA samples to the Government Laboratory for analysis was not challenged.

(d) The defendant was arrested by DSPC 49191 on 17 August 2010 at 1020 hours for the present offence. Under caution, the defendant said “I don’t know”.

(e) In 2010, DSPC 51398, PW3 in these proceedings, took DNA samples from the defendant, labeled AA227424. Forensic scientist Luk Duen Yee, PW1 in these proceedings, examined the DNA samples obtained from the defendant. The continuity and authenticity of the DNA samples collected from the defendant was not challenged.

(f) Government chemist Ho Siu-hong, PW5 in these proceedings, had examined the DNA samples obtained from bottle A, labeled GPL 4604 and the DNA samples of the defendant, labeled AA227424.

(g) The movement record of the Immigration Department, exhibit P6, disclosed that the defendant was in Hong Kong at the material time of the burglary.

6.  Although reference was made in the admitted facts to ‘witness statements’ prepared by PW1, PW2 and PW5 in respect of their handling of the DNA samples, these ‘witness statements’ were not produced in evidence.                                                    

7.  PW1, Ms Luk Duen Yee is a forensic scientist working in the Government Laboratory, and has been one since June 2002.  Her expertise was not challenged by the defence. She examined the buccal swab samples obtained by DSPC 51398 from the defendant and submitted for analysis on 16 August 2010.  The 2 buccal swabs, each contained in a tube, were sealed in a tamper proof evidence bag and labeled AA 22742 – after receiving them, she labeled each tube with a unique laboratory reference number, DDU 3037 and DDU 3038 respectively.  She extracted the DNA from the buccal swab sample labeled DDU 3037 and analyzed the extracted DNA using the amplification kit called identifiler marketed by Applied Bio-systems, which analyzed 15 different DNA systems together with a sex determining system – the purpose of her examination was to determine the DNA profile of the donor of the DNA on the buccal swab sample, ie the defendant herein.  The result would be compared with the DNA profile of the donor of the DNA found from the crime scene sample by her colleagues in the Biological Sciences Section.  She was able to determine that the sex of the donor was male.  As she was able to successfully extract the DNA from the buccal swab sample labeled DDU 3037, she did not need to use the buccal swab sample labeled DDU 3038.  She recorded the results of her findings and this was produced and marked as exhibit P9.  The source for her findings as recorded in exhibit P9 was an electro-pherogram (hereinafter referred to as an ‘EPG’) which was produced and marked as exhibit P10.  The DNA sample which passes through the genetic analyzer would be transformed and represented as peaks, and the numbers beneath each peak are the number of repeats of a specific DNA region, which represents an individual’s DNA characteristics, as can be seen from exhibit P10.  She also prepared at the same time the typing table, exhibit P11, which sets out the results of her examination of the sample marked AA 227424.

8.  In examination-in-chief, she said that to her knowledge, unless a DNA sample donor had an identical twin, the DNA sample donor would be the only person who could have such DNA profile – it was unlikely for someone else to have an identical DNA profile.  She agreed under cross-examination that siblings of the same parents often shared genetic markers at several locations, but it would not be identical at all locations.  However, she emphasized that that was not her area of expertise, nor was she an expert in the statistical area – her role here was to conduct the DNA profile testing of the samples that she received, ie the defendant’s DNA samples.  She added that she based her comment in respect of only identical twins having identical DNA profiling from articles, journals and text books.

9.  PW2, Dr Lai Kam-ming, is employed as a chemist at the Forensic Science Division of the Government Laboratory since 1991.  His expertise was not challenged by the defence.  His major responsibilities include the detection and identification of human body materials such as semen, blood, etc and the analysis of such.  In March 2003, he was attached to the Biochemical Sciences Section of the Government Laboratory, and his main duties included the examination of case exhibits collected from crime scenes for the presence of human bodily materials and the subsequent analysis using DNA profiling techniques in order to determine their possible source.  On 10 March 2003, DPC 47123 delivered a number of items to the Government Laboratory for analysis, including a cotton swab labeled GPL 4604.  Human DNA was detected after analysis of the sample.  The DNA was from a single source.  He used DNA profiling techniques and sex typing tests to establish the DNA profile of the DNA extracted from the sample as well as the sex of the donor, and from his results concluded that the donor was male. At the time, the re-agent kit used by the Government Laboratory analyzed 9 DNA systems.  The DNA typing table he prepared was produced and marked as exhibit P12.  The relevant entry is that for the sample with the lab reference GPL 4604.  He prepared exhibit P12 from the test results that were recorded and checked by him, at page 17 of the case file, which was produced and marked exhibit P14.  His colleague, Dr H L Wun, also checked the results, which was at page 16 of the case file, and produced and marked as exhibit P13.  The EPG from which he obtained the results that he recorded on exhibit P14 was produced and marked as exhibit P15.  He did not detect any abnormality nor anything suspicious in the test results.  From about 2005 to 2006, 15 DNA systems have been analyzed including the 9 that were examined in 2003 using the identifiler re-agent kit. In his experience, there was only one occasion when samples of DNA of a pair of identical twins were examined and the DNA result of the 2 samples was indistinguishable.

10.  Leave was sought by the prosecution to recall PW2 after the testimony of PW5, Dr Ho, as a result of questions put to PW5.  The defence had no objection to PW2 being recalled, and I granted the prosecution application.  

11.  PW2 was questioned about whether he had kept a log of when he had been given the samples and where he had kept these.  He confirmed that he had kept such a record, on the back of his case file.  No issue was taken that the photocopy of that log be produced, and it was produced and marked as exhibit P18, and shows the movement records of the samples retrieved at the scene which were sent to the Government Laboratory for analysis.  PW2 received the sample marked GPL 4604 on 2 August 2003 from ‘F9C’, the freezer for storage of samples located in the strong room of the reception counter of the Government Laboratory, and stored it in a locked bin marked ‘KML1’ in his section “BSS” ie the Biochemical Sciences Section.  He returned the samples on 16 December 2003, and these were returned to the police on 6 February 2004.  PW2 described how he dealt with the sample cotton swab marked GPL 4604 – how he extracted the DNA from the sample in solution form.  He used a portion of the extracted DNA for analysis using the profiler+ reagent kit.  He stored the balance DNA in solution form in a freezer.  Exhibit P23(1) to (4) are four photos that depicted how the balance DNA solution was stored.  The tube containing the balance DNA solution was marked with a label ‘L4604-M’, as shown on photos 3 and 4, and then the tube was stored in the box marked ‘DF5 2C Box 7’ shown in photo 1, in the first row under the number ‘2’ as depicted in photo 2.  DNA solution stored in the freezer could be preserved, even for 10 years, if properly extracted and stored, which he confirmed was the case in respect of the DNA extracted from the sample marked GPL 4604.  He was asked about whether he had come across genotyping errors being committed by the Laboratory caused by using the reagent kit profiler+.  He said he could not recall any such error in the couple of thousand of such analysis that were carried out.  The reagent kit identifiler was first used in the Laboratory in around 2005 to 2006 – it was used because it could analyze 15 DNA systems compared with 9 using profiler+, thus information in 6 more DNA systems could be obtained, and thus he felt that identifiler was superior to profiler+.  There was also a world-wide trend to replace profiler+ with identifiler.  He  said that the reliability of profiler+ had not been questioned by the forensic community worldwide, but readings from profiler+ and identifiler could be different because of the different design of the 2 re-agent boxes, and he viewed the identifiler as the more superior.  He also said that it was more preferable to use the same re-agent box to analyze samples.

12.  PW3, DSPC 51398, testified that on 26 August 2010, he collected the DNA sample of the defendant herein.  He had attended a course in buccal swab sampling in 2006, and thereafter had been obtaining DNA samples from suspects.  He explained the procedure for obtaining such samples – he had to apply for a Pol 1065 form from his superior, whose rank should be that of superintendant or above, and then he had to prepare a set of Pol 1066 forms in duplicate, and he would bring along a set of buccal swab tools, the apparatus required to obtain buccal swab samples, and he would then go to see the suspect.  Pol 1065 is the authorization for obtaining DNA samples from a suspect, and authorizes him to use reasonable force to obtain the DNA sample if the suspect is unco-operative.  Pol 1066 is the form to be signed by the suspect indicating his consent for DNA samples to be taken from him.  After the suspect has indicated his consent and signed on Pol 1066, he would then begin to obtain the DNA sample from the suspect.  He produced sample DNA collection kit, exhibit P16, what he had used to obtain the DNA sample from the defendant.  He confirmed that exhibit P4 and P5, which had been produced by agreement, were the Pol 1066 and Pol 1065 forms in respect of the defendant. The defendant had signed on exhibit P4 to indicate he consented to the DNA sample being taken from him, and that he understood the procedure and purpose of the taking of the DNA sample from him.

13.  The exhibits marked exhibits P1 to P7 were admitted into evidence by agreement between the prosecution and defence.  Exhibit P1 was the handover form of DNA sample exhibit, wherein PC 51211 handed over the exhibits as set out in the form, being the exhibits seized from the burgled premises with potential DNA traces including the latent DNA swab taken from the opening of the 2 distilled water bottles, to DPC 47123 on 27 February 2003.  Exhibit P2 is the form referred to as Pol 160, setting out the exhibits that were delivered by DPC 47123 to the Government Laboratory for forensic examination and included the DNA swab taken from the 2 bottles of distilled water.  Exhibit P3 was the Pol 160 form referred to by PW3 in his testimony, which he handed over to the Government Laboratory together with the 2 DNA buccal samples that he had obtained from the defendant for forensic DNA examination.  Exhibit P4 was the Pol 1066 form, ‘notice to person under section 59C of the Police Force Ordinance (Cap 232 as amended) provision of non-intimate sample’ that PW3 served on the defendant explaining to him about the obtaining of the buccal swabs from him and the purpose for so doing – the defendant had signed on this form to confirm that he had been informed of the contents of the notice and he gave his consent for the taking of the buccal swab samples for forensic analysis and acknowledged receipt of the notice.  Exhibit P5 is the form Pol 1065 PW3 referred to in his testimony, wherein he was authorized to obtain the buccal swab samples from the defendant.

14.  PW4, PC 51211, was the police officer who had lifted the DNA samples using cotton swabs from the mouths of the 2 distilled water bottles at the burgled premises, which he had marked ‘A’ and ‘B’.  The 2 swabs with the DNA samples were labeled by the Government Laboratory as GPL 4604 and GPL 4605 respectively.  He had received training on human swab sampling and also on the collection of DNA materials from crime scenes.  He had collected the exhibits at the burgled premises and subsequently handed these to DPC 47123 – he had no reason to believe that the DNA samples had been contaminated.  He rubbed the cotton swabs around each of the exhibit bottles and put these swabs into sterilized plastic tubes, and labeled them and sealed the tubes in a plastic bag with adhesive tapes and signed on the plastic bag.  He kept the DNA samples in his custody until he handed these to DPC 47123.

15.  PW5, Dr Ho Siu-hong, has been employed in the Forensic Science Division of the Government Laboratory since December 2000 as a government chemist, and his major duties include the detection and identification of human body materials such as semen, blood, etc and the individualization of such by using DNA technology.  His expertise was not challenged by the defence.  He conducted a comparison of the DNA sample labeled GPL 4604 taken from a bottle and the DNA sample from the defendant labeled AA 227424 to see if the DNA profiles of the two matched.  He compared the DNA profiles obtained by PW1 and PW2, exhibits P9 and P12 herein, and found that it matched in all of the DNA systems tested except one.  He described it as a ‘partial match’ as allele 11 was detected in the analysis conducted by PW2.  When PW2 had conducted his analysis of the crime scene DNA sample in 2003, he had used a re-agent kit that examined 9 DNA systems, profiler+, whilst PW1 had analyzed the DNA that she obtained from the buccal swabs obtained from the defendant using a reagent kit that examined 15 DNA systems, identifiler, which included the 9 DNA systems that were examined by PW2.  The result for the DNA system D8S1179 differed – the other systems all matched.  He concluded that the difference in results could be because the results were obtained using two different DNA typing methodologies using different DNA typing reagent kits.  The DNA had been of good quality and the typing results looked fine as well.  From his own experience, he felt it was best to confirm the results by re-testing the DNA obtained from the distilled water bottle, marked GPL 4604, from the burgled premises using the same re-agent kit as that used by PW1, ie the identifiler, which examined 15 DNA systems and could provide more information about more DNA systems for comparison.  PW2 had preserved the DNA he had extracted from the swab with human DNA detected marked GPL 4604.  PW5 retrieved the DNA solution that had been preserved from the storage location after obtaining authorization from his senior and conducted a retest for the DNA profile using the identifiler reagent kit.  The test was successfully conducted and he obtained the DNA profile, and found that it matched completely with the DNA profile obtained from PW1 from the defendant’s DNA.  He had prepared appendices I and II to his statement, which were produced and marked exhibit P17.  Appendix I disclosed the DNA typing results of the DNA from the cotton swab marked GPL 4604 as reported by PW2 using the profiler+ reagent kit whilst appendix II disclosed the DNA typing results of the re-analysis conducted by PW5 of the preserved DNA obtained from the cotton bud swab marked GPL 4604 using the identifiler reagent kit.  The EPG for the re-analysis was also produced and marked as exhibit P22.  PW5’s re-analysis confirmed that the donor of the DNA was a male.  PW5 also calculated the ‘RMP’ ie the approximate combined random match probability of the DNA types that a randomly selected person in the local Chinese population unrelated to the possible donor as stated in the possible source column, ie the defendant, to be 1 in 45 quadrillion.  The Hong Kong Government Laboratory kept a database of a few hundred DNA profiles, and this was verified statistically to be reliable, and was a well accepted way to calculate random match probability.  The logs showing that he had retrieved the preserved DNA from the sample GPL 4604 from the freezer for re-analysis were produced and marked exhibits P19 and P20.  PW5 was satisfied that the preserved DNA had been properly stored in the freezer – the temperature of the freezer where it was stored was monitored continuously.  Had it not been properly stored, the DNA would have degraded and he would not have been able to obtain the DNA profile when he conducted the re-analysis.  Here he was able to complete the re-analysis successfully and there was no indication of DNA degradation.  He was satisfied with the integrity of the sample when he retrieved it from the place where it had been stored – the packing and seal were all intact.  PW5 also referred to the record, marked exhibit P21, which disclosed the method used to extract the DNA from the sample cotton bud marked GPL 4604.  He was cross-examined about the discordance between the two reagent kits – profiler+ and identifiler.  He said the discordance was first reported in international scientific journals in 2003 approximately.  The profiler+ kit could not detect the allele16 in the D8S1179 DNA system – this was not known when the profiler+ reagent kit was developed.  It was only after it had been used for a number of years that it became known that there were occasions that the kit could not detect such rare DNA characteristics.  The newer reagent kits, including identifiler, could detect the rarer genetic characteristics such as allele 16.  In his view, it did not mean that the identifiler reagent kit was more accurate than the profiler+ reagent kit – he emphasized the importance of using the same reagent kit when comparing DNA samples.  Because the rare genetic characteristic allele 16 was detected, it reinforced the match of the 2 DNA samples and the reliability of the test result – the presence of such genetic characteristic was not a common one.  PW5 was also cross-examined in respect of the random match probability calculation that he had made.  His calculation was based on the donor of the crime scene DNA sample and the defendant being unrelated.  He agreed that if the actual donor of the crime scene DNA was a relative of the defendant, this might affect the calculation.  But it was unlikely to be a complete match, as was the situation here.  He was referred to a publication called ‘Dealing with DNA evidence - a legal guide’ written by Andrei Semikhodskii, published in 2007.  The views expressed therein were the views of the author.  There was nothing put before me as to the qualifications of the author, save that in the preface, it was mentioned that he was a director of Medical Genomics Ltd.  At page 146 of his book, Mr Semikhodskii wrote that where it was alleged that the crime in question might have been committed by a relative of the accused, the random match probability would grossly overestimate the value of DNA evidence.  He referred to a table in ‘Statistical analyses to support forensic interpretation for a new ten-locus STR profiling system, (2001) published by Foreman LA and Evett IW in the Int J Leg; Med 114:147-55.  PW5 said he had come across the table, but it was based upon the use of the SGM Plus Marker system, and not the profiler+ or identifiler systems.  The table put the match probability where the donor could be the sibling of the accused at 1 in 10 thousand, and where the donor was a parent at 1 in 1 million, and where the donor was an uncle at 1 in 1 million, a nephew at 1 in 10 million, and first cousin 1 in 100 million and if unrelated at 1 in 1 billion.  He agreed that if relatives were factored into the random match probability calculation, there would be a difference.  But PW5 also said that in his calculation, he had been conservative, and had not taken account of the rare genetic characteristic detected, allele 16.  He agreed that there was a higher probability of a relative having the same match, although he could not calculate it.

16.  There was one defence witness, Ng Kam Hing, the elder brother of the defendant.  He produced a family tree of their family which he had prepared, marked exhibit D1, showing four generations of their family and the male relatives.  In their immediate family, the defendant had two brothers, one being DW1 Ng Kam Hing.  The defendant does not have an identical twin.  He has 12 male cousins.  DW1 was unclear about the exact whereabouts of his male relatives at the time of the burglary in 2003.  Some lived in China, although they did visit Hong Kong occasionally.  He himself had never been to the burgled premises in 2003. 

17.  The crux of the prosecution case is the DNA evidence.  The defendant has made no admissions – under caution when he was arrested, he said ‘I do not know’.  Although strictly that is not a denial, nor is it an admission, and little can be attached to what he said under caution.

18.  That there had been a burglary at the material time was not challenged.  Prosecution witnesses were cross-examined at length about how the crime scene DNA was obtained and stored, and how they were analyzed, and how they were kept thereafter.  I was satisfied that the crime scene samples, in particular the cotton bud marked GPL 4604 used to collect the DNA sample from the crime scene from the distilled water bottle found on the table had been properly obtained and kept and had not been contaminated in any way prior to it having been delivered to the Government Laboratory for analysis.  I was satisfied too that the DNA samples had been properly obtained from the defendant and properly stored and had not been contaminated in any way prior to their delivery to the Government Laboratory for analysis.  I was satisfied too that both PW1 and PW2 had properly extracted the DNA from the samples they received, and properly conducted their respective analyses of the samples, and the results were contained in the tables produced by them, as exhibited.  PW2 had properly stored the preserved DNA from the cotton bud marked GPL 4604, and PW5 had retrieved this preserved DNA for re-analysis using the identifiler reagent kit, and the results of his retesting is contained in the table produced by him.

19.  PW5 was asked to do a comparison of the results obtained by PW1 and PW2.  Because of the discordance in these results, which he concluded was because of the different reagent kits used in the analyses, he conducted a re-analysis of the preserved DNA using the same reagent kit as that used by PW1, which examined more DNA systems and was the more advanced one which is currently used by the Government Laboratory, and the results he obtained matched completely with that obtained by PW1.  What this demonstrated was that the DNA profile of the donor of the DNA obtained from a distilled water bottle left at the burgled premises matched the DNA profile of the defendant.  The statistical chance of selecting a person at random from the local Chinese population who would share the same DNA profile was one in 45 quadrillion.  In his calculation of random match probability, PW5 did not take into account the possibility that a relative of the defendant might be in the pool of potential contributors to the crime scene sample.  The initial result obtained by PW2 using the profiler+ reagent kit differed from that of PW5 using the identifiler reagent kit.  PW5 did not seek to reanalyze the preserved DNA using the profiler+ reagent kit again to verify PW2’s findings as he did not think it was necessary.  PW2 maintained that both reagent kits were still retained and used by the Government Laboratory.

20.  DNA evidence does not establish or conclude that a defendant is the offender.  It demonstrates that the defendant could be the offender.  Its weight will depend on what else is known about the offender and what other evidence is presented against him.  Here, there is no other evidence against him, save that he was in Hong Kong on the night the premises were burgled.

21.  In R v Doheny & Adams, 1997 1 Cr App R 369, the proper approach to be adopted where DNA evidence is involved is set out.  There are 12 points to consider.  I have considered these.

22.  The defence did not challenge the statistical validity of the databases used.  However, the random match probability calculation was queried in cross-examination.  PW5 accepted that if the possibility that the sample came from a relative of the defendant was included in the calculation, this would affect the ratio.  There are methods of calculation that take this into account.  However, he was unable to do the calculation and provide this figure to the court.

23.  In the table referred to in the book produced by the defence, table 9.1 at page 146, where there is a sibling of the accused, the match probability is 1 in 10 thousand, a significantly lower figure than that provided by PW5.  Here although DW1 said that he had not been to the burgled premises, the defendant does have another male sibling.

24.  The burden of proof is on the prosecution to establish that it was the defendant who drank from the distilled water bottle found in the burgled premises.  I am not satisfied to the requisite standard that the burden has been discharged by the prosecution.  I would say that I do find it extremely suspicious, but the burden of proof is one of proof beyond all reasonable doubt.  I do have doubt, and the benefit of doubt must be to the defendant.  He is acquitted of the charge.