Scottish High Court of Justiciary Decisons

APPEAL COURT, HIGH COURT OF JUSTICIARY

[2015] HCJAC 22

HCA/2014-1525/XC

Lord Eassie

Lord Malcolm

Lord Wheatley

OPINION OF THE COURT

delivered by LORD EASSIE

in

APPEAL AGAINST CONVICTION

by

DAVID DUNBAR

Appellant;

against

HER MAJESTY’S ADVOCATE

Respondent:

Appellant:  P Brown; John Pryde & Co, Edinburgh

Respondent:  Scullion QC, AD;  Crown Agent

13 March 2015

[1]        On 20 February 2014 the appellant was convicted, along with a co-accused, Wayne Ernest Johnston, of a charge of being concerned in the supplying of the controlled drug diamorphine, contrary to section 4(3)(b) of the Misuse of Drugs Act 1971.  The co-accused was also convicted of a charge of being concerned in the supplying, at the same loci and within the same period of time, of the controlled drug cocaine. The jury acquitted the appellant of that charge.

[2]        The prosecution was brought following the receipt in HM Prison Saughton of a postal box which, having aroused some suspicion on the part of the prison authorities, was examined by police officers.  The officers found the box to contain a plastic carrier bag within which were five books.  Within the spine of each of those books was a sealed brown paper envelope.  Four of those envelopes contained powder which on subsequent analysis was found to include diamorphine.  The fifth envelope also contained a quantity of powder which, in the case of that envelope, contained cocaine.

[3]        The postal markings on the package indicated that the packet had been posted at a post office in Leith.  CCTV footage from the post office in question was recovered.  The footage showed the co-accused, Wayne Johnston, entering the post office with another man, Thomas Seath.  Mr Seath was also charged, with the same charges, on the same indictment but his plea of not guilty was accepted by the prosecutor prior to the commencement of the trial of the appellant and Mr Wayne Johnston.  The CCTV footage showed Mr Seath  purchasing the postal box, placing within it the carrier bag containing the books, and thereafter closing, addressing and posting the box - all in the presence of the co-accused Mr Johnston.

[4]        As respects the appellant, however, the only evidence tendered by the prosecutor was the evidence of one of two forensic scientists[1] who had examined a mouth swab taken from the appellant by police officers and portions of the paper envelopes, including the seal area, which had been found in the spines of the books within the carrier bag in the postal box.  It is an important feature of this case that no other admissible evidence was offered which referred to the appellant or might link the appellant to the supply of the powders containing diamorphine or cocaine to the addressee of the postal box.

[5]        At the close of the Crown case the solicitor acting for the appellant advanced a submission that there was no case to answer.  The submission was to the broad effect that such evidence as had been presented by the prosecutor was insufficient to implicate the appellant in the supply.  The presiding sheriff rejected that submission and the essential issue in this appeal is whether the evidence offered by the Crown was sufficient to enable conviction of the appellant.

[6]        As we have already narrated, the Crown case against the appellant was confined to the “DNA evidence” given by the forensic scientist. The scientist gave evidence that she and a colleague had examined the portions of the envelopes submitted to them with a view to ascertaining whether there was on them any organic material from which, by appropriate scientific analysis, a DNA profile might be obtained. This, of course, was with a view to comparing such profile as might be obtained from any material on the envelopes with a profile more readily obtainable from the cellular material in the saliva in the mouth swab provided by the appellant to the police.   Organic material, and evidence of DNA profiling derived from it,  was found on a number of the envelopes and was invoked  by the prosecution in its the case against the co-accused, Mr Johnston. But only one of the envelopes disclosed the presence of some organic material said to be relevant to the appellant.

[7]        In relation to the evidence of the scientist respecting the outcome of the comparison made between the material on that envelope and the reference sample provided by the appellant, the sheriff sets out the relevant part of the scientists’ report:

“DNA was extracted from any cellular material present on the above item and the incomplete DNA profile obtained, which was male in origin, matched the respective parts of the DNA profile of the mouth swab taken from [the appellant].  The probability of finding such matching DNA profiles if a male other than [the appellant] is the source of this DNA is approximately one in four million.  The above statistic has been derived from a database of Caucasians and assumes that any other possible source of this DNA is not related to [the appellant]”.

The scientist was unable to say whether the cellular material detected on the portion of the envelope was contained in saliva or any other bodily fluid.  She accepted that the presence of the material could readily result from direct contact in other ways than the depositing of saliva or bodily fluid; and the material could equally arrive on the envelope by secondary transfer.  It was not possible to express any view as to the time at which the material might have been deposited or transferred.  The forensic scientist also acknowledged that the database from which her estimate of probabilities was derived excluded any male related to the appellant.

[8]        Both before the sheriff and before us it was pointed out on behalf of the appellant that – obviously – an envelope is a very movable item.  One was therefore not in the situation of cellular material deposited on an immovable object or structure at a crime scene.  There was no evidence as to when or in what circumstances the material came to be deposited.  In particular there was no evidence that the material was contained in saliva or any body fluid.  By analogy with cases such as Slater v Vannett 1997 JC 226 and Campbell v HM Advocate [2008] HCJAC 50; 2008 SCCR 847, both of which involved reliance solely on the detection of an accused’s fingerprint on a similar movable article, namely a plastic bag, counsel submitted that the DNA evidence tendered against the appellant was likewise, on that account alone, insufficient to found a conviction.

[9]        In allowing the case to go to the jury, the sheriff accepted the prosecutor’s contention that, since the area of the envelopes submitted for examination contained the seal, not only did the envelope bear the “accused’s DNA” but also that it was to be inferred that “the accused’s DNA” appeared on the envelope because he had licked and sealed the envelope.  Since the appellant had thus licked and sealed the envelope he must by virtue of that action have knowledge of its contents.

[10]      While at the trial much of the argument may have been focussed on the movable nature of an envelope there is – as counsel submitted- another important aspect to the question whether the evidence tendered by the Crown was sufficient to allow the appellant to be convicted.  Evidence of the extent of a match between DNA profiles from material on a crime scene sample and a reference sample is not to be assimilated in all respects to the absolutist nature of fingerprint evidence with which practitioners and the courts have traditionally been familiar. That traditional absolutist conception of the nature of fingerprint evidence has become in very recent years a matter of debate and is largely no longer accepted in current forensic science,  but  at least following Hamilton v H M Advocate 1934 JC 1 it was generally accepted by fingerprint scientists, practitioners and consequently the courts in Scotland that if 16 points of identity in the minutiae were found between the crime scene fingerprint and the known fingerprint of the suspect the former could be taken to be an imprint in fact made by the suspect. The fingerprint is in such circumstances conceived as being unique.  In the case of fingerprint evidence, it has thus been possible traditionally to speak of the fingerprint on the crime scene sample as being “that of the accused”.   

[11]      However, evidence of the extent of the matching of DNA profiles may be different in important respects.  First, whereas a fingerprint requires the person in question actually to have touched the article upon which the impression is found, the cellular material on the crime scene sample which is subject to DNA examination does not necessarily arise from digital contact.  The material may have arrived on the article by a wide variety of means, including a secondary transfer.  Secondly,  but importantly in the present case, evidence of the extent of a match between the examined sample and the reference sample is commonly expressed in terms of the probability of finding a similar match from another individual.  The basis for expressing such a probability derives from a database of donated samples from individuals, usually grouped in the database by ethnic origin.  In many cases, the estimated probabilities derived from the selected probability model are such that it may be materially inaccurate to speak of “the accused’s DNA” being found on the crime scene sample; there is thus not the unique identification traditionally associated with fingerprint evidence, which in practice has been led only when the 16 points of coincidence have been detected by the expert examiner. 

[12]      In the present case the evidence from the forensic scientist was that the probability of finding such a matching DNA profile if a male other than the appellant, and unrelated to the appellant, were the source of the crime scene DNA was approximately one in four million.  That estimation of probability is very far from attributing, or even approaching, the uniqueness of identity traditionally attaching to fingerprint evidence with sixteen points of coincidence. It means that in a population of the size of that of the United Kingdom, in addition to the appellant, cellular material from seven or eight males unrelated to the appellant will give a DNA profile matching that derived from the cellular material on the envelope in question.  Put another way, in statistical terms the probability that the source of the material on the envelope was from an unrelated male in the UK other than the appellant is of the order of 7/8, or 0.87(87%).  The location of those other, unrelated males at any time within that population group cannot of course be known. Additionally it may be added that the database from which the probability estimate was derived excluded related males; and, of course, there was no evidence that the envelope in question had not had a wider circulation than within the UK. At the outset, therefore, the extent of the match, and the statistical probabilities spoken to by the scientist, do not in themselves provide a sufficient link to the appellant. They simply indicate a possibility that he, among an indeterminate plurality others, may be a possible source of the crime scene cellular material.

[13]      In addition to that important flaw in the prosecution case, as was pointed out by counsel for the appellant in his criticism of the sheriff’s decision to accede to the prosecutor’s contention that the “accused’s DNA” appeared on the envelope because the accused had licked the seal, there was no evidence that the organic material on the envelope derived from saliva.  The scientific evidence accepted that the material could equally have been deposited by other means (such as digital contact) or have been transferred by a secondary process. A police officer had given evidence that the area of the seal was an area which might be licked in sealing the envelope, but that was not in any way evidence that the cellular material detected by the scientists was contained in saliva. Assuming the envelope were one requiring the application of moisture, that was – as the sheriff remarks - simply self evident; but, it may be added, that there was seemingly no evidence that the seal on the envelope in question employed an adhesive which required the application of moisture.

[14]      In my view there is much force in this criticism of this aspect of the sheriff’s decision.  The boundary between speculation and the drawing of an inference may sometimes be difficult to define with precision. But in this case, in which there was no evidence that the cellular material came from saliva, or was even likely to have come from saliva, I consider that inviting the jury to reach the important conclusion – crucial to the prosecution case - that the material was deposited by the licking of the seal of the envelope does indeed fall on the side of speculation. There was no other evidence to which the jury might have resort by way of supplement to the scientist’s evidence in order to found any inference going beyond her report of the scientific findings. But they were invited in effect to make a finding going well beyond the scientific evidence, but on no additional or other evidential material, that the cellular material from which the partial profile was extracted was indeed deposited in saliva.

[15]      As I have already stressed, there was no other evidence whatever before the jury capable of incriminating the appellant.  Had there been such other evidence, the scientific evidence regarding the matching of the DNA profile might have had some possible supportive probative value.  But, in my view, on its own, the particular DNA evidence led in this case was plainly insufficient to permit the conviction of the appellant.

[16]      In these circumstances, I consider that the appeal succeeds and that the conviction should be quashed.

APPEAL COURT, HIGH COURT OF JUSTICIARY

[2015] HCJAC 22

HCA/2014-1525/XC

Lord Eassie

Lord Malcolm

Lord Wheatley

OPINION OF LORD MALCOLM

in

APPEAL AGAINST CONVICTION

by

DAVID DUNBAR

Appellant;

against

HER MAJESTY’S ADVOCATE

Respondent:

Appellant:  P Brown;  John Pryde & Co

Respondent:  Scullion QC, advocate depute;  Crown Agent

13 March 2015

[17]      I have had the advantage of reading a draft of Lord Eassie’s opinion.  Given the inadequacy of the statistical evidence linking the DNA sample to the appellant (as discussed at paragraph 12 of his Lordship’s opinion), I agree that the appeal should be upheld and the conviction quashed.  I reserve my opinion on whether, that difficulty aside, the evidence would have entitled the jury to infer that the appellant sealed the envelope.

APPEAL COURT, HIGH COURT OF JUSTICIARY

[2015] HCJAC 22

HCA/2014-1525/XC

Lord Eassie

Lord Malcolm

Lord Wheatley

OPINION OF LORD WHEATLEY

in

APPEAL AGAINST CONVICTION

by

DAVID DUNBAR

Appellant;

against

HER MAJESTY’S ADVOCATE

Respondent:

Appellant:  P Brown;  John Pryde & Co

Respondent:  Scullion QC, advocate depute;  Crown Agent

13 March 2015

[18]      I have had the opportunity of reading the opinions of both Lord Eassie and Lord Malcolm in draft.  I agree that the weight of the statistical evidence linking the DNA sample to the appellant is not, in the circumstances, sufficient by itself to justify a conviction.  As this was the only evidence against him, it follows that his appeal succeeds and the conviction should be quashed.

[19]      I do not think it is appropriate in this appeal to take a view as to whether the evidence could not properly have been considered by the jury, and, if so, what conclusions or inferences might have been taken from it.