Neutral Citation Number: [2011] EWCA Crim 1295
Case No: 201004692 B1
IN THE COURT OF APPEAL (CRIMINAL DIVISION)
ON APPEAL FROM THE CROWN COURT AT LUTON
His Honour Judge Bright QC
Ind nos. T20097336 & T20090352
Royal Courts of Justice
Strand, London, WC2A 2LL

Date: 25/05/2011
Before :

LORD JUSTICE RICHARDS
MR JUSTICE RODERICK EVANS
and
HIS HONOUR JUDGE NICHOLAS COOKE QC
(sitting as a Judge of the Court of Appeal Criminal Division)
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Between :

	The Queen	Respondent	
	- and -		
	Ashley Kieron Thomas	Appellant	

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David Hughes (instructed by Shaw, Graham & Kersh Solicitors) for the Appellant
Jane Bickerstaff (instructed by the CPS) for the Respondent

Hearing date : 7 April 2011
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Judgment

Lord Justice Richards : 
1.	On 11 June 2010, following a trial at Luton Crown Court before His Honour Judge Bright QC and a jury, the appellant, Ashley Keiron Thomas, was convicted of possession of a prohibited firearm (count 1) and, by a majority of 10 to 2, of causing grievous bodily harm with intent (count 3).  Count 3 was an alternative to a charge of attempted murder (count 2) on which he was acquitted.  He had previously pleaded guilty to an offence of dangerous driving (count 4).  A sentence of imprisonment for public protection, with a minimum term of 6½ years (less time spent in custody on remand), was imposed on count 3, with a concurrent sentence of 7 years’ imprisonment on count 1 and no separate penalty on count 4.
2.	An appeal is now brought, with leave of Eady J, against the convictions on counts 1 and 3.   The issues in the appeal are (1) whether the trial judge erred in refusing to exclude certain DNA evidence adduced by the Crown, (2) whether his summing-up to the jury in respect of that DNA evidence was adequate, and (3) whether he erred in ruling against a submission of no case to answer on count 3.
3.	The events giving rise to the charges occurred in Luton in the early hours of 26 May 2009, the date of the carnival in the town.  At about 2.00 a.m. an altercation occurred at a club known as “Traffick”, starting in the foyer and spilling out onto the road outside.  It was not disputed that the appellant was involved in the altercation or that, as a result of being kicked and punched, he sustained a number of injuries including a bloodied nose.  A number of shots were fired, one of which wounded a man called Opey Akinboro in the groin.  Shortly afterwards a BMW motor car driven by the appellant and containing two other black males was seen driving away from the scene.  The car was followed by the police and in the ensuing pursuit it was driven at excessive speeds and in a dangerous manner.  It came to a sudden stop in a residential road and the two passengers got out and ran off down an alleyway.  The car drove off again at speed until it failed to negotiate a roundabout and crashed.  The appellant was thereupon arrested for dangerous driving.  The following day two firearms, namely a Baikal pistol and a Brocock revolver, were recovered from a garden adjacent to the alleyway down which the two passengers had run on leaving the appellant’s car.  
4.	The prosecution case was that the appellant was in possession of the Baikal pistol and fired a shot from the pistol into the groin of the victim.  Part of the evidence relied on was DNA evidence.  A blood stain was found on the underside of the firearm slide of the pistol.  All the components of the appellant’s DNA were found to be present in the blood stain.  The interpretation of that evidence was the subject of disagreement between the expert witnesses.  The essence of the dispute was that the prosecution expert, Miss Cornelius, considered the results to “provide support” for the view that some of the DNA on the gun was from the appellant; whereas the defence expert, Dr Syndercombe-Court, was of the opinion that it was not possible to go further than that the results “could not exclude” the appellant as a contributor to the DNA on the gun.  An application was made on behalf of the defence at trial that the DNA results and Miss Cornelius’s opinion about them should be excluded.  The judge rejected that application.  A challenge to his ruling, at least in so far as it related to Miss Cornelius’s opinion about the results, is the first of the issues on the appeal.  
5.	In addition to the DNA evidence, the prosecution relied on other evidence to link the appellant with the Baikal pistol and to show that he was in close contact with the victim.  CCTV footage from the scene showed him to have an object tucked into his waistband:  the prosecution invited the inference that this was the pistol.  A hat that the appellant had been wearing was used by the victim to stem the bleeding from the gunshot wound, indicating that the appellant must have been in close proximity to him.  The prosecution further relied on the evidence of a forensic scientist, Geoffrey Warman, that gunshot residue found on the appellant’s clothing was consistent with direct exposure to the firing of the pistol.  
6.	At the close of the prosecution case there was a submission of no case to answer on counts 2 and 3, on the basis inter alia that there was no evidence on which the jury could be sure that the bullet in the victim’s groin was fired from the Baikal pistol as contended by the prosecution.  The judge ruled against that submission.  A challenge to his ruling is the third of the main issues in the appeal.
7.	The appellant gave evidence that he had travelled to Luton to attend the carnival.  He was stopped and searched by the police.  He went to a local park where there were a large number of people smoking and drinking.  He saw a man he knew as “Jamali”, together with Jamali’s brother.  At about 12.00 to 12.30 a.m. he left the park in his car, accompanied by Jamali and his brother.  Another group of friends followed in another car.  The group went initially to a different nightclub, then to Traffick.  Seeking to explain the sequence of events on the CCTV footage, he said that he went first with Jamali to enquire as to the cost of entry and to see if there was a good atmosphere inside.  He returned to his car and took a bottle of drink from his boot.  He, together with all but two of the rest of the group, then returned to the club.  He entered the club, paid the entrance fee and was searched.  Those searching him found half a cannabis joint in his pocket, so he went outside with Jamali to smoke it, then went back into the club.  He did not have a firearm with him.  On his way back into the club he brushed past a stocky black male who punched him in the eye and then struck him again.  He went to ground and blacked out.  When he came round he was on the floor with two or three people stamping on him.  He crawled to the front door to try to escape.  Once outside, he was still under attack and trying to protect himself.  As he was being assaulted he heard two shots very close over the top of him.  The attack stopped and he managed to get to his feet and to stumble to his car.  He heard more shots fired as he made his way back to the car.  
8.	The appellant said that as he started the car the doors opened and Jamali and his brother got in.  He drove away and became aware of a police car behind him.  Jamali’s brother told him not to stop the car and pressed an object into his side.  He went to push it away but noticed it was a gun.  Jamali’s brother threatened to shoot him if he did not drive on, and directed him to the spot where he stopped the car and Jamali and his brother got out and ran away.  The only firearm he saw was the one carried by Jamali’s brother.  He was not aware of Jamali or his brother being in possession of a firearm until they were in the car.
9.	The issue for the jury on count 1 was whether the appellant had the Baikal pistol in his possession at any point during 26 May.  The issue on counts 2 and 3 was whether he attempted to murder the victim or, alternatively, whether he shot him intending to cause him grievous bodily harm.
10.	The judge’s summing up was clear and thorough.  The only complaint made about it concerns the passage in which he set out the disagreement between the two experts concerning the interpretation of the DNA evidence.  In the alternative to the submission that the opinion of the prosecution expert should not have been admitted into evidence at all, it is submitted that the judge failed to give the jury the guidance they needed as to how to resolve the disagreement between the two experts.
The expert DNA evidence
11.	The DNA evidence in the case was considered by the experts in the light of the observations of the Court of Appeal in R v Reed and Reed [2010] 1 Cr App R 23 concerning, in particular, the reliability of Low Template DNA evidence and the Low Copy Number (LCN) process (see [71]-[75] of the court’s judgment).  
12.	The stain from the firearm slide on the Baikal pistol was tested using Second Generation Mix Plus (SGM+) and LCN techniques.  The results indicated the presence of DNA from at least three individuals.  There was no major profile.  The quantity of DNA was low.  A joint note agreed by the experts following a meeting between them recorded as follows:
“Both Dr Syndercombe-Court and Miss Cornelius were in agreement that the level of DNA present bordered the threshold described in the R v Reed and Reed ruling and was such that stochastic effects needed to be considered.
It was agreed that the level of DNA amplification was good, but that it deteriorated at the high molecular weight loci, as expected.  None of the alleles observed were below threshold. 
It was agreed that stutters and artefacts had been considered and taken into account.
It was agreed that the results had a good level of reproduction generally, with only low levels of possible drop in.
It was agreed that there were variable levels of stochastic variation throughout the result, which could be due to the relatively low amount of DNA and the enhanced process used.  It was agreed that the stochastic variation at all loci except D2, D18 and FGA was minimal or acceptable.  It was agreed that the stochastic effects at the high molecular weight loci, in particular D2 and FGA, were the main reason for not being able to assume the prominent alleles were from one contributor and therefore, there was no major profile.
It was agreed that all of the components of Ashley Thomas’ DNA profile were represented within the LCN results obtained.
It was agreed that the results were unsuitable for any kind of statistical evaluation.
….
Summary
Dr Syndercombe-Court and Miss Cornelius agreed on the quality of the result and that it was suitable for some interpretation, but not for statistical evaluation as the stochastic effects at the high molecular weight loci introduced some doubt as to whether the prominent alleles were from more than one person.  However, the phrasing and significance of finding all of the components of Ashley Thomas’ DNA profile represented within the LCN results was not agreed upon ….”
13.	We have omitted those parts of the agreed note which described the difference of view between the experts as to the interpretation of the results, since that requires fuller exposition.  Exploration of this and related matters occupied several days at an early stage of the trial and involved the making of numerous witness statements as well as the giving of oral evidence in a voir dire.
14.	Miss Cornelius’s view was encapsulated in the following passage from her final witness statement, dated 20 May 2010:
“To reiterate:  all of the components of Ashley Thomas’ profile appear in the DNA mixture.
I have considered the following two propositions:
•	Ashley Thomas was a contributor and some of the DNA recovered was from him; or
•	Ashley Thomas was not a contributor and none of the DNA recovered was from him.
If the first alternative were true, I would expect all of the components in Ashley Thomas’ profile to be present in the mixed DNA result.
If the second alternative were true, I would have a low expectation of finding components which matched all of the components of Ashley Thomas’ profile in the DNA mixture, as simulation experiments have indicated that it is rare to observe all 20 components by chance alone.
Therefore, in my opinion, the DNA profiling evidence provides support for the view that some of the DNA recovered was from Ashley Thomas, but I am unable to quantify the level of this support.
Furthermore, I agree that there are many other combinations of DNA components in different profiles that could produce the mixed results obtained.”
15.	As to the “simulation experiments” mentioned in that passage, Miss Cornelius gave a footnote reference to a Forensic Science Service (“FSS”) manual, which said no more than that “Unpublished simulation experiments have shown that it is rare to observe all twenty alleles by chance”.  She stated in evidence that the experiments had been conducted by a scientist within the FSS but had not been completed because of the ill health of the scientist.  It was accepted before us that she had not herself seen details of the experiments and that such details were not provided to the defence although they had been requested by Dr Syndercombe-Court.  
16.	Whilst in her statement Miss Cornelius referred only to the simulation experiments for the proposition that it is rare to find all 20 components by chance alone, she expressed herself more broadly in her oral evidence, as appears from the following passage in the judge’s summing-up (94C-D):
“She said that her experience, however, as a forensic scientist for 12 years, dealing in DNA supported the findings of the simulation experiments and agreed with the conclusion drawn from them that it was rare to find all 20 components of a DNA profile by chance.”
17.	The summing-up went on, however, to spell out concessions made by Miss Cornelius which underline the limited significance to be attached to the DNA evidence even on the basis of Miss Cornelius’s view of the matter:
“However, she agreed that the bottom line was that she could give no statistical evaluation of what the word rare meant and she accepted that her findings really did not enable her to say that the defendant had handled the Baikal pistol.”
18.	As to Dr Syndercombe-Court, in her last witness statement, dated 20 May 2010, she expressed the view that the DNA results were “incapable of reliable interpretation”.  Evidently, however, she moved on in the course of discussions with Miss Cornelius.  In her oral evidence to the jury she said that the results were “on the edge of scientific interpretation”.  The experts’ joint note makes clear that she had come to accept that the results were “suitable for some interpretation”.  As to the interpretation of them, however, she preferred wording that had been discussed at some point between Miss Cornelius and two senior colleagues within the FSS but had been rejected by Miss Cornelius, namely that there were no features in the mixed profile recovered from the pistol which would exclude the appellant as a contributor.  As the judge summarised it in his summing-up (97C-E):
“She said that in scientific terms, the most you could say from the DNA results was that you could not exclude – this is the form of words she is keen to sign up to – she said that the results could not exclude the defendant from being a contributor to the DNA mixture, but she fundamentally disagreed with the opinion expressed by Miss Cornelius that the results provided support for the view that some of the DNA may have come from the defendant.  She said that was going too far.
She said that Miss Cornelius’ opinion in her view was based on the assumption that the 20 components which matched the defendant’s profile have come from one individual, whereas it is not possible, she said, as a scientist to say that they have all come from one person.”
19.	It may be noted that the FSS manual referred to by Miss Cornelius discourages the use of wording such as “could not exclude” because it is often misunderstood and may be seen as implying a measure of support for the presence of the suspect’s DNA.  That consideration may have had some influence on Miss Cornelius but is ultimately of no consequence here.  Miss Cornelius made clear her view that the results did provide support for the presence of the appellant’s DNA on the pistol, whereas Dr Syndercombe-Court made equally clear her disagreement with that view and that her use of “could not exclude” did not imply any measure of support for the presence of his DNA on the pistol.  
20.	For completeness we now set out the parts of the experts’ joint note that we previously omitted:
“Dr Syndercombe-Court felt that Miss Cornelius’ interpretation (when she said that ‘it is rare to observe all 20 components by cahnce’) was of a type known as ‘Random Man Not Excluded’ or probability of inclusion/exclusion, which is accepted for use in other European countries but is not generally accepted in this country for use in court due to its limitations and inherent prosecution bias.  Miss Cornelius disagreed with this view and felt that her evaluation used the likelihood ratio framework, but she also conceded that she did not have an in-depth knowledge of RMNE calculations and had not dealt with RMNE in a casework setting as it was not used by the Forensic Science Service.
Miss Cornelius felt that making the comment that Ashley Thomas could not be excluded as a contributor, but without qualifying this comment further could lead to misunderstanding.  Dr Syndercombe-Court disagreed and stated that to go further required an assumption that the prominent alleles must be from one individual.  Miss Cornelius disagreed with the requirement of making that assumption.
Dr Syndercombe-Court preferred the suggested alternative wording that was in Miss Cornelius’ casefile record of the discussion with Drs Evett and Pope, but Miss Cornelius stated that the alternative wording did not change the conclusion that had been agreed during the discussion.
Summary
…
Dr Syndercombe-Court is of the opinion that ‘providing support’ is overstating the evidence.  Miss Cornelius is of the opinion that making no further comment than ‘cannot exclude’ is failing to provide additional scientific information that could be of use to the court.”
21.	It is evident from the judge’s summing-up that the point about “Random Man Not Excluded” was difficult to follow in the evidence.  It has played no part in the submissions on the appeal and we need say no more about it.
The application to exclude the DNA evidence
22.	An application was made to the judge to exercise his discretion to exclude the DNA results obtained by Miss Cornelius and her opinion about them, on the ground that the results were not reliable, her opinion was not scientifically based and the admission of her evidence would have such an adverse effect on the fairness of the proceedings that it should not be admitted.  
23.	In his ruling the judge referred to R v Reed and Reed (cited above).  He was satisfied that the agreed note accurately set out the matters upon which the experts agreed and those which remained in contention.  He said that, most importantly, the experts were agreed that the results were “suitable for qualitative interpretation, but not for statistical evaluation”.  He continued:
“The courts of England and Wales have become familiar with the kind of statistics commonly associated with DNA profiling, but whereas here, a statistical evaluation is not possible, I see no reason why experts should not be permitted to express an opinion on whether the results provide support for the view that some of the DNA recovered was from the defendant, as the Crown’s expert contends, or whether they merely establish that the defendant cannot be excluded as a contributor to the DNA mixture as the defence expert argues.”
24.	Referring to R v Atkins [2009] EWCA Crim 1876, he said that forensic experts, including those specialising in such things as footwear, fibres and facial mapping, express opinions on their findings in this way, ranging from “lends no support” to “lends powerful support” to the case for the prosecution.  The absence of a statistical evaluation of likelihood was no bar to such evidence being given before a jury.
25.	The experts were agreed that the quality of the DNA results was sufficiently good to enable them to be subject to expert interpretation and evaluation.  The results were therefore admissible in principle.
26.	He referred to the fact that Miss Cornelius had placed reliance on unpublished simulation experiments mentioned in the FSS manual, and to the defence objection to reliance on that material.  He cited R v Weller [2010] EWCA Crim 1085, in which it was held that a court determining whether there was a sufficiently reliable scientific basis for expert evidence to be given was entitled to take into account unpublished papers and the experience of experts.  In his view the FSS manual fell into that category and Miss Cornelius was entitled to refer to it to support her opinion.
27.	The judge looked further at the evidence of the two experts, pointed out that the significance of DNA evidence depends to a large extent upon the other evidence in the case, and referred to the fact that the appellant, in his defence case statement and the instructions given to another forensic scientist instructed by the defence, had sought to give an innocent explanation for the presence of his DNA on the pistol.  He said that the jury should be entitled to assess the DNA evidence against the background of the other evidence in the case.  He concluded:
“There is no doubt that the DNA experts for the prosecution and the defence take a different view as to how the DNA results should be interpreted.  The criticisms made by the defence of the opinion expressed by Miss Cornelius can be fully aired before the jury and in my judgment, there is nothing unfair about the jury being allowed to hear and decide for themselves about the different opinions expressed by the two DNA experts.
In the circumstances, this is not a case for the exercise of my discretion under s.78 of the Police and Criminal Evidence Act 1984 to exclude the evidence of Miss Cornelius.”
The appeal against the ruling
28.	The grounds of appeal contend that the judge erred in refusing to exclude the DNA evidence in respect of the cellular material on the Baikal pistol, and Mr Hughes’s written submissions contained passages directed at the entirety of the DNA results, contending that they were insufficiently reliable for them to be placed before the jury.  In the course of his oral submissions, however, it became apparent that the real target of the challenge was the judge’s refusal to exclude the opinion of Miss Cornelius that the DNA results “provide support” for the view that the appellant was a contributor to the DNA recovered from the pistol.  Mr Hughes said that if her opinion had been excluded the DNA evidence would not have been led by the prosecution since it would have lacked probative value and would not have assisted the prosecution case.
29.	We should make clear that we have heard nothing to cast doubt on the correctness of the judge’s ruling that the DNA results themselves were admissible in evidence.  The results were the subject of thorough consideration by both experts in the light of R v Reed and Reed, and agreement was ultimately reached that they were suitable for some interpretation.  There has been no attempt to take issue with or to go behind that agreement.  It has therefore been unnecessary for us to give detailed consideration to what was said in R v Reed and Reed or in the later case of R v Broughton [2010] EWCA Crim 549 as to the circumstances in which Low Template DNA using the LCN process can produce reliable results.  The focus before us has been on whether the judge was right to allow Miss Cornelius to give her particular interpretation of the results.
30.	Mr Hughes’s criticisms of the judge’s refusal to exclude Miss Cornelius’s opinion had two main strands to them.  One was that the opinion should have been excluded because Miss Cornelius was unable to give any further explanation of the words “provide support”:  she could not say how much support they provided.  As the experts’ agreed note made clear, it was not possible to make any statistical evaluation of the results.  There are some areas, such as that of facial mapping, where no statistical database exists and an expert may give a subjective opinion by reference to a recognised sliding scale.  But that situation does not apply here and Miss Cornelius’s opinion was not based on any such scale.  She said nothing which could assist the jury in their assessment of the weight of the evidence.  Mr Hughes contrasted this with what Miss Cornelius was able to say about blood on the steering wheel of the appellant’s car, where a full profile was obtained and she estimated that “it is of the order of a billion times more likely that this profile would have been obtained if the blood had come from Ashley Thomas, rather than from someone else, unrelated to him”.
31.	The other main strand of the criticisms was that details of the simulation experiments upon which Miss Cornelius based her opinion had not even been seen by her, let alone disclosed to the defence.  Mr Hughes submitted that on the particular facts of this case there was an insufficient body of relevant knowledge or experience, sufficiently organised and recognised, to be accepted as reliable or to provide a reliable basis for Miss Cornelius’s opinion.
32.	For the Crown, Miss Bickerstaff submitted that the judge’s ruling was entirely correct.  The experts were agreed that the DNA results were of a sufficient quality to allow for interpretation, and the only point of difference was in the level of interpretation or how to express the results.  Miss Cornelius agreed that the appellant could not be excluded as a contributor to the DNA on the pistol but thought that to stop there was unsatisfactory and that it was more accurate to say that the results “provide support” for the presence of the appellant’s DNA on the pistol.  In reaching that view she not only had regard to the unpublished simulation experiments referred to in the FSS manual but relied, as she was entitled to do, on her own experience, telling the jury that she had never before found a case where all 20 of the components of a DNA profile were present by chance.  In any event, by the end of the evidence the difference between the two experts had been reduced almost to a distinction without a difference, since Miss Cornelius agreed in terms that her findings really did not enable her to say that the appellant had handled the pistol.
33.	That point led into a series of submissions about the strength of the case against the appellant even without Miss Cornelius’s opinion as to the support provided by the DNA evidence.  The case was based on a large number of pieces of circumstantial evidence from different sources.  It included evidence that the appellant had lied about his movements earlier that evening; the evidence concerning his movements outside the club, including the CCTV showing an object tucked into his waistband; evidence putting him in close proximity to the victim at the time of the shooting; a lying explanation he gave to the police as to why he had a bloody face; and evidence from the specialist in gunshot residue that the appellant’s clothing had been directly exposed to the discharge of cartridges from the Baikal pistol and the Brocock revolver. 
34.	Although the points raised by Mr Hughes have caused us a degree of hesitation, we have concluded in the end that the judge was entitled to allow Miss Cornelius’s opinion into evidence and that by the end of cross-examination the difference of view between the two experts had ceased in any event to be of any real significance.
35.	It is a troubling feature of Miss Cornelius’s evidence that, while feeling able to express the opinion that the results “provide support” for the view that the appellant was a contributor to the DNA recovered from the pistol, she was unable to give any indication of the degree of support so provided.  The nearest she got was in her explanation that it was “rare” to find all 20 components of a DNA profile by chance; but even then she did not indicate how rare it was or what this meant for the degree of support provided by a finding that all 20 components were present.  
36.	It is true, as the judge said in his ruling, that the absence of a statistical evaluation of likelihood is not an automatic bar to the giving of an expert assessment.  There are fields, such as facial mapping, where, in the absence of a statistical database, it is open to experts to express subjective opinions by reference to a sliding scale ranging, for example, from “lends no support” through “lends support” to “lends powerful support”.  The relevant principles were considered in R v Atkins [2009] EWCA Crim 1876, to which the judge referred.  The judgment of the court includes the following:
“23.  On principle, we accept the caution with which any expression of conclusion in relation to evidence of this kind (and others) needs to be approached.  We agree that the fact that a conclusion is not based upon a statistical database recording the incidence of the features compared as they appear in the population at large needs to be made crystal clear to the jury.  But we do not agree that the absence of such a database means that no opinion can be expressed by the witness beyond rehearing his examination of the photographs.  An expert who spends years studying this kind of comparison can properly form a judgment as to the significance of what he has found in any particular case.  It is a judgment based on his experience.  A jury is entitled to be informed of his assessment.  The alternative, of simply leaving the jury to make up its own mind about the similarities and dissimilarities, with no assistance at all about their significance, would be to give the jury raw material with no means of evaluating it …
31.  We conclude that where a photographic comparison expert gives evidence, properly based upon study and experience, of similarities and/or dissimilarities between a questioned photograph and a known person (including a defendant) the expert is not disabled either by authority or principle from expressing his conclusion as to the significance of his findings, and that he may do so by use of conventional expressions, arranged in a hierarchy, such as those used by the witness in this case ….  They are, however, expressions of subjective opinion, and this must be made crystal clear to the jury charged with evaluating them.”
37.	As Mr Hughes submitted, the situation here is very different from that under consideration in Atkins.  Miss Cornelius was not purporting to apply a sliding scale or to give the kind of structured evaluation that the facial mapping expert was seeking to provide in that case.  The very absence of that feature is one of the reasons why her opinion was so unsatisfactory.  On the other hand, the judge below was entitled to draw from R v Atkins the point that an expert assessment based on experience may be admissible even in the absence of a statistical evaluation of likelihood, provided that the matter is approached with suitable caution and the nature of the assessment is made crystal clear to the jury. 
38.	A further concern about Miss Cornelius’s evidence is the reliance she placed on the unpublished simulation experiments referred to in the FSS manual.  It is well established that experts are not limited to reliance on published papers but may rely on unpublished papers and on their own experience and experiments:  see R v Weller [2010] EWCA Crim 1085 at [47]-[49].  The difficulty about the simulation experiments in this case is not that they were unpublished but that Miss Cornelius seems to have known virtually nothing about them beyond the bare statement in the FSS manual that “Unpublished simulation experiments have shown that it is rare to observe all twenty alleles by chance”.  Taken by itself, that would provide an extremely thin basis for Miss Cornelius’s statement of opinion about the significance of the DNA results; and there is the added concern that, in the absence of any further information about the simulation experiments, the defence expert had no way of assessing their significance.  Ultimately, however, it seems that Miss Cornelius based her opinion not just on the simulation experiments but on her own lengthy experience as a forensic scientist, which she said supported the findings of the experiments and agreed with the conclusion drawn from them; and in so far as she based herself on her own experience, she was plainly entitled to do so.
39.	Despite those concerns about the substance of Miss Cornelius’s opinion and the basis for it, we take the view that the evidence was admissible and that the judge was entitled not to exclude it in the exercise of his discretion under s.78 of the Police and Criminal Evidence Act 1984.   Miss Cornelius’s credentials as an expert were not in dispute.  Her opinion could not be said to have been so unreliable or so lacking in foundation as to make it inadmissible or to compel its exclusion in the interests of fairness.  It was of potentially greater assistance to the jury to have this evidence than to be denied it altogether.  The appropriate course was for the evidence to be adduced and then to be tested in cross-examination, so that its limitations and its weight could be assessed by the jury.  
40.	In the event, the practical effect of cross-examination in this case was to reduce virtually to vanishing point any significance that might otherwise have been attached to Miss Cornelius’s opinion.  As the judge put it in summing-up (see [17] above), “she accepted that her findings really did not enable her to say that the defendant had handled the Baikal pistol”.  The difference between Miss Cornelius and Dr Syndercombe-Court became, to adopt the words used by Miss Bickerstaff in her submissions, almost a distinction without a difference.  Despite all the attention given to it, the DNA evidence proved in the end to be a side-show.   This, as it seems to us, was the result of the proper application of the adversarial process to evidence properly adduced.  But it also means that even if, contrary to our view, the judge was wrong to allow Miss Cornelius’ opinion to be adduced, its admission into evidence can confidently be stated to have had no adverse effect on the safety of the appellant’s convictions.
41.	In the circumstances we need not spend time examining the rest of the evidence against the appellant, though we accept Miss Bickerstaff’s submission that it established a strong case against him. 
The judge’s directions to the jury on the DNA evidence
42.	The second issue in the appeal is very closely related to the first and can be dealt with briefly.  Mr Hughes submitted that if the judge was right not to exclude Miss Cornelius’s opinion that the DNA evidence “provides support” for the presence of the appellant’s DNA on the pistol, it was necessary for him to give, but he failed to give, a specific direction or guidance to the jury as to how to approach that evidence.  
43.	The judge gave a general direction to the jury in correct and conventional terms as to the nature and status of expert evidence, directing them inter alia that it was for them to decide whose evidence and whose opinions, if any, they accepted.  When dealing with the DNA evidence relating to the pistol, he gave a detailed, accurate and balanced summary of the evidence of the two experts.  Thus far there is no complaint about the summing-up.  It is submitted, however, that the judge should have gone further, so as to give the jury some assistance on how to approach their consideration of the views expressed by the experts and the significance of the difference between those views.  In a complex and disputed area of DNA interpretation it was not sufficient simply to summarise the evidence of the two experts and to leave it at that.
44.	We reject those submissions.  In our judgment, it was sufficient in this case for the judge to deal with the matter as he did, by means of a full and fair summary of the expert evidence itself, without attempting to give guidance on how to choose between the expert opinions or how to decide what weight to give them.  In any event, as we have made clear, the difference between the experts came down in the end to almost nothing; and the judge reminded the jury in clear terms of the concessions made by Miss Cornelius.  The summing-up on this issue was plainly adequate. 
The submission of no case to answer
45.	At the close of the prosecution case, Mr Hughes made a submission of no case to answer on the counts of attempted murder and of causing grievous bodily harm with intent.  The judge rejected that application for reasons handed down at the time but read into the record at a later date.  In those reasons the judge referred to a body of evidence linking the appellant with the Baikal pistol and found that the jury would be entitled to infer that the bullet which hit the victim, Mr Akinboro, must have come from the pistol.  In challenging that ruling on this appeal, Mr Hughes accepts the existence of a body of evidence linking the appellant with the Baikal pistol but submits that the evidence did not enable the jury to be sure that the bullet which hit the victim came from the pistol.
46.	In summarising the evidence earlier in this judgment we have referred to two weapons, namely the Baikal pistol and the Brocock revolver, recovered from the area where the two passengers got out of the appellant’s car and ran off after the incident.  
47.	The evidence was that the Baikal pistol fired 9 mm bulleted cartridges and that, on firing, the cartridge case was ejected from the pistol.  The pistol had a magazine which took up to seven cartridges.  A number of fired 9 mm cartridge cases were recovered from the scene and were found to have been fired by the pistol.  Each had fired a jacketed bullet.  Also recovered were a copper bullet jacket with marks indicating that it had been fired by the pistol, and a fired lead core from a 9 mm jacketed bullet.  Thus, all of the ammunition scientifically linked to the pistol was jacketed.  It is, however, important to note that one of the prosecution experts, Ms Hannam, gave evidence that the pistol was also capable of firing unjacketed bullets, which could be produced by a method known as “home loading” of empty cartridge cases.   This was, in her experience, uncommon but it was not beyond the bounds of possibility.
48.	The Brocock revolver fired .38 special calibre cartridges.  It had a revolving cylinder taking up to six cartridges.  The cartridge cases remained in the cylinder after firing.  Two cartridge cases were recovered from the revolver.  One had been ruptured on firing.  The other, which had not itself been fired, was loaded in the cylinder next to the fired cartridge and was damaged when the rupture occurred.  Both cartridges fired unjacketed bullets.  A single fired, unjacketed .38 lead bullet was recovered from some waste land on Cheapside about 100 yards from the club, near to the junction with Guildford Street.  A comparison of the firing marks was inconclusive as to whether the bullet had been fired from the revolver:  Ms Hannam gave evidence that it could have come from the revolver (and could have been the bullet discharged from the empty cartridge case) or it could have come from a similar weapon. 
49.	The bullet that hit the victim remained in his groin, so that the experts were unable to examine it directly and it was not possible to say with certainty which firearm it came from.  Mr Griffiths was the expert witness who gave evidence about this.  The relevant part of his evidence is summarised as follows in the judge’s summing-up:  
“Mr Griffiths explained that he had looked at x-rays showing the bullet still lodged in Mr Akinboro’s body.  He also examined Mr Akinboro’s clothing and he concluded that the bullet was slightly distorted and you will remember how he took you through the photographs of Mr Akinboro’s clothing ….  They show that the bullet hole was at the top of the zipper of Mr Akinboro’s jeans and that there are two or three teeth missing, and he concluded that what he saw would account for the damage to the bullet shown on the x-ray.
He told you that he carried out tests on the bullet hole in the jeans and the pants beneath to see if there were any traces of copper or nickel which you know are both used to make jackets for bullets, and he found on the edge of the bullet hole that there was a deposit of lead, but could find no evidence of copper or nickel.  He concluded that this could either be because the bullet was an unjacketed lead one, or that it was a jacketed bullet fired through a dirty barrel which would mask any copper or nickel that might be present.”
In cross-examination, as the judge also reminded the jury, Mr Griffiths accepted that the fact that the tests had been positive for lead and negative for copper and nickel “made it most likely that the bullet which entered Mr Akinboro’s body was an unjacketed one”.  
50.	Mr Hughes’s submission that there was no case to answer relied heavily on the evidence of Mr Griffiths that the bullet in the victim was “most likely” an unjacketed bullet.  He submitted that whilst, in accordance with Ms Hannam’s evidence, it might be theoretically possible for the Baikal pistol to fire unjacketed bullets, there was no such type of ammunition recovered from the scene and all of the ammunition scientifically linked to the pistol was found to be jacketed.  As to the evidence of Mr Griffiths that it was possible that the bullet in the victim was a jacketed bullet fired through a dirty barrel, Mr Hughes pointed out that  Ms Hannam had test fired the Baikal pistol but there was no evidence that it had a dirty barrel.  He also contended that the damage to the bullet in the victim was a pointer to it being an unjacketed lead bullet, lead bullets being softer than jacketed bullets.  
51.	This line of argument was directed towards the defence contention that the bullet in the victim may have come from the Brocock revolver, which fired unjacketed bullets, rather than from the Baikal pistol as contended by the prosecution.  An apparent difficulty facing that contention was that only one bullet had been fired from the Brocock revolver, and a .38 calibre bullet which could have been fired from the revolver was recovered from the scene.   The defence sought to meet that difficulty, however, by suggesting the existence of a third firearm, which would account for that bullet and would open up the possibility that the bullet fired from the Brocock revolver was the bullet that hit the victim.
52.	The suggestion was based on the evidence of PC Davies, a member of the armed response unit with 18 years’ experience who attended the scene in a police car after Mr Akinboro had been shot.  His evidence was that as they drove along Guildford Street (which adjoins Cheapside) they passed several ambulances which had parked and were awaiting their attendance.  A little further along he stopped the police car.  He continued:  
“As I got out of the police car, I heard a gun shot.  The area is heavily built up with lots of tall concrete buildings which cause sound to reverberate.  It was not possible to say where the sound came from.”
53.	This was relied on as evidence that a third gun was discharged in the vicinity shortly after the shooting of Mr Akinboro but after the appellant had driven off with the Baikal pistol and the Brocock revolver in his car.  It was said that the unjacketed bullet found on the waste land near the junction of Cheapside and Guildford Street may have been fired from that third gun.  The bullet fired from the Brocock revolver would then be a viable candidate for the bullet remaining in Mr Akinboro’s groin.  
54.	That is the basis on which it was submitted that the jury could not be sure that the victim was hit by a bullet fired from the Baikal pistol as alleged by the prosecution and that there was therefore no case for the appellant to answer.
55.	We are satisfied that the judge was right to reject the submission.  Despite the concession by Mr Griffiths that the bullet in the victim was “most likely” to be an unjacketed one, it remained possible on the forensic evidence that the bullet in the victim (whether jacketed or unjacketed) was fired by the Baikal pistol.  Further, the suggestion that the bullet was fired by the Brocock revolver depended on the existence of a third gun, which depended in turn on PC Davies’s evidence that he heard a gun shot when he arrived on the scene a significant period of time after the victim had been shot.  But PC Davies’s evidence on that point stood alone and unverified:  nobody else heard a gun shot at that time.  It remained a reasonable inference that the bullet recovered from the waste ground had come from the Brocock revolver and that the revolver had been fired only once.  There was, moreover, evidence that the bullet that hit the victim was fired from close to him, and evidence putting the appellant close to him at the time.  Further, the gunshot residue evidence showed particles from the Baikal pistol not only on the front of the appellant’s clothing but also on the back, consistent with the prosecution case that one of the shots from the pistol had been fired by the appellant either above his head or behind him to deter anyone from following him as he ran back to his car to make a getaway.  Taking everything together, it was open to a reasonable jury to conclude that the bullet that hit the victim had been fired by the Baikal pistol, not by the Brocock revolver, and that the appellant was responsible for firing it.  The judge was right to conclude that the issue was properly one for the jury and therefore to leave counts 2 and 3 for their consideration.
Conclusion
56.	For the reasons given, we are not persuaded that the judge erred in any of the ways put forward on the appellant’s behalf or that there is any reason to doubt the safety of the conviction.  The appeal against conviction is dismissed.