“(1) Where, in any proceedings against a person for an offence, evidence is given that the accused— (a) at any time before he was charged with the offence, on being questioned under caution by a constable trying to discover whether or by whom the offence had been committed, failed to mention any fact relied on in his defence in those proceedings; or (b) on being charged with the offence or officially informed that he might be prosecuted for it, failed to mention any such fact, being a fact which in the circumstances existing at the time the accused could reasonably have been expected to mention when so questioned, charged or informed, as the case may be, subsection (2) below applies (2) Where this subsection applies— (a) a magistrates’ court inquiring into the offence as examining justices; (b) a judge, in deciding whether to grant an application made by the accused .. (c) the court, in determining whether there is a case to answer; and (d) the court or jury, in determining whether the accused is guilty of the offence charged, may draw such inferences from the failure as appear proper.” (a) at any time before he was charged with the offence, on being questioned under caution by a constable trying to discover whether or by whom the offence had been committed, failed to mention any fact relied on in his defence in those proceedings; or (b) on being charged with the offence or officially informed that he might be prosecuted for it, failed to mention any such fact, (a) a magistrates’ court inquiring into the offence as examining justices; (b) a judge, in deciding whether to grant an application made by the accused .. (c) the court, in determining whether there is a case to answer; and (d) the court or jury, in determining whether the accused is guilty of the offence charged, may draw such inferences from the failure as appear proper.”
“Since s.34 (2) (c) permits the court to draw proper inferences when determining whether there is a case to answer, the section may apply at a stage of the trial when the defendant has had no opportunity to give or adduce evidence, and when it will not be known (perhaps not even decided) whether the defendant will give or call evidence or not. But the court is likely to know, from questions put to prosecution witnesses, what (if any) positive case the defendant advances. It would be surprising if sub-section (2)(c) were intended to apply only when, unusually, specific suggestions put to a prosecution witness are accepted by the witness.”
“Mr Thwaites drew our attention to a number of authorities including Re J-S [1981] Fam. 22, Gordon[1995] 1 Cr.App.R. 290 and Adekunle (unreported transcript, January 26, 1993), a decision of Judge Smedley Q.C. None of these provides any support for Mr Thwaites' proposition that DNA evidence alone is incapable of proving guilt. That is unsurprising. In every case, the probative effect of a particular piece of evidence depends on its quality individually and in relation to all the other evidence. It is, in our view, wrong to describe DNA evidence generally, or the DNA evidence that was presented in this case, as no more than a rough estimate of that which it seeks to establish. …. Any of the figures mentioned, taken on their own, are plainly very cogent evidence. However, whether the evidence of those figures is reliable in itself depends on scrutiny of the assumptions and methodology of the original calculations, which can be the subject of enquiry at trial. The extent to which such evidence survives such scrutiny sufficiently to establish guilt is, as we have said, a separate question to be assessed in the light of all the evidence in the case. There is, however, nothing inherent in the nature of DNA evidence which makes it inadmissible in itself or which justifies a special, unique rule, that evidence falling into such a category cannot found a conviction in the absence of other evidence.”
“If no fact is known about the Defendant, other than that he was in the United Kingdom at the time of the crime the DNA evidence tells us no more than that there is a statistical probability that he was the criminal of 1 in 26. The significance of the DNA evidence will depend critically upon what else is known about the suspect. If he has a convincing alibi at the other end of England at the time of the crime, it will appear highly improbable that he can have been responsible for the crime, despite his matching DNA profile. If, however, he was near the scene of the crime when it was committed, or has been identified as a suspect because of other evidence which suggests that he may have been responsible for the crime, the DNA evidence becomes very significant. The possibility that two of the only 26 men in the United Kingdom with the matching DNA should have been in the vicinity of the crime will seem almost incredible and a comparatively slight nexus between the defendant and the crime, independent of the DNA, is likely to suffice to present an overall picture to the jury that satisfies them of the defendant's guilt. The reality is that, provided there is no reason to doubt either the matching data or the statistical conclusion based upon it, the random occurrence ratio deduced from the DNA evidence, when combined with sufficient additional evidence to give it significance, is highly probative. As the art of analysis progresses, it is likely to become more so, and the stage may be reached when a match will be so comprehensive that it will be possible to construct a DNA profile that is unique and which proves the guilt of the defendant without any other evidence. So far as we are aware that stage has not yet been reached.”
“It appears to us that there can be no possible ground of objection in principle to the leading of DNA evidence by the Crown, based as it is or should be on empirical statistical data, the data and the deductions drawn from it being available for the defence to criticise and challenge. The more difficult question is whether the fact that the prosecution are permitted to adduce evidence of that kind should lead to the conclusion that the defence should be at liberty to deploy evidence in support of the Bayesian approach to non-scientific, non-DNA evidence, as was done in this case.”
“It would seem to us that this was a case properly approached by the jury along conventional lines. That would involve them perhaps in asking themselves at the outset whether they accepted wholly or in part the DNA evidence called by the Crown. If the answer to that was “no”, or uncertainty as to whether the answer was “yes” or “no”, then that would be the end of the case. If, however, the jury concluded that they did accept the DNA evidence wholly or in part called by the Crown, then they would have to ask themselves whether they were satisfied that only X white European men in the United Kingdom would have a DNA profile matching that of the rapist who left the crime stain. It would be a matter for the jury, having heard the evidence, to give a value to X. They would then have to ask themselves whether they were satisfied that the defendant in question was one of those men. They would then go on to ask themselves whether they were satisfied that the defendant was the man who left the crime stain, bearing in mind on the facts of this case the obvious discrepancies between the victim's description of her assailant and the appearance of the appellant, the victim's failure to identify the appellant on the identification parade and the evidence of the appellant and the witnesses called by him. Consideration of this last question would of course involve the jury in assessing all the points made concerning the victim's opportunity to see her assailant, the likelihood of her description being accurate or inaccurate in all the circumstances, the significance of her failure to identify the appellant, the strength and weakness of the evidence given by the appellant and his witnesses, and all other matters relied on by the defence. Of course, it is a matter for the jury how they set about their task, and it is no part of this Court's function to prescribe the course which their deliberations should take. But consideration of this case along the lines indicated would in our judgment reflect a normal course for a properly instructed jury to adopt. It is the sort of task which juries perform every day, carefully and conscientiously, on the evidence, as they are sworn to do. We do not consider that they will be assisted in their task by reference to a very complex approach which they are unlikely to understand fully and even more unlikely to apply accurately, which we judge to be likely to confuse them and distract them from their consideration of the real questions on which they should seek to reach a unanimous conclusion. We are very clearly of opinion that in cases such as this, lacking special features absent here, expert evidence should not be admitted to induce juries to attach mathematical values to probabilities arising from non-scientific evidence adduced at the trial.”
“… the problem which arises here, as it seems to us, is simply that here if the jury discounted the figure of seven to ten in order to allow for those who would be too young to have committed this offence and those who would be too old to have committed it, they would still be left with a nucleus figure say, for the purposes of argument, in the region of five or six. If it were possible to have placed alongside all of the five or six men in the United Kingdom who would have been in that group, what, one asks oneself, would the jury have said? How could they be sure which of them committed the offence? This highlights the difficulty in relying on DNA evidence alone where there was absolutely no other evidence to set alongside it.”
“The fact of the matter is that there was on the balaclava DNA material from two different people, possibly more than two different people. From that evidence, it seems to us that it was always going to be impossible for the prosecution to satisfy the jury so that they were sure, that this appellant was the man who was wearing the balaclava at the time that the robbery was committed. For instance, suppose the prosecution was able to identify that the other person whose partial DNA was on the balaclava, and he or she was arrested, it would not be possible without more to identify with certainty which of the two committed the robbery. That was a problem, or a hurdle which the prosecution always faced and, it seems to us, that that difficulty provides the answer to this appeal.”
“By the time of Grant and Ogden, analytical techniques had advance considerably, and here the evidence was that there was one in a billion chance of the DNA matching someone else. However, the difficulty in those cases was that the expert evidence could not age the DNA. It was not possible to show that the DNA was placed on the balaclava in Grant, or on the scarf in Ogden, at the time of the offence. Once again, it is possible to see immediately why, in the absence of any other evidence, there was insufficient evidence on which a jury could convict. However, we consider that these decisions are distinguishable. The present case differs from all of these cases in that the presence of DNA is not relied on as evidence of the presence of the defendant at a particular place at a particular time; rather, the essence of the offence is possession of the article. So there is a much closer connection in this case between the DNA evidence and the commission of the offence. The presence of DNA on the article, on the muzzle of a gun in this case, is capable of being evidence of possession of the article at some point before 15th August as alleged in the indictment.”
“What then do the authorities establish? It is clear from the authorities that where a movable item is left at the crime scene with mixed DNA profiles, one of which matches the defendant's profile, that on its own is not sufficient to support a conviction. Indeed, the proposition may possibly be true if the DNA profile is not mixed because people can handle an object without depositing DNA, therefore even if the only DNA on an object is that of the defendant, it does not inexorably follow that no one else will have touched that object. On the other hand, the authorities also establish that that DNA evidence in conjunction with other evidence pointing against the defendant can be very compelling - see the statement of principle by Phillips LJ in Doheny and Adams. See also the reasoning of the Court of Appeal in Darnley. ”
“In our judgment, there is no sustainable criticism to be made of the judge’s conclusion that there was a case for this jury to consider. The evidence from the experts did afford such evidence and, having regard to that which transpired thereafter, there could not be any ground, if there was a prima facie case for the jury, for regarding the conviction as being in any way unsafe.”