"(6) The prosecutor is also, as we have said, the primary judge of whether or not a witness to the material events is incredible, or unworthy of belief. It goes without saying that he could not properly condemn a witness as incredible merely because, for example, he gives an account at variance with that of a larger number of witnesses, and one which is less favourable to the prosecution case than that of the others.
"(7) A prosecutor properly exercising his discretion will not therefore be obliged to proffer a witness merely in order to give the defence material with which to attack the credit of other witnesses on whom the Crown relies. To hold otherwise would, in truth, be to assert that the prosecution are obliged to call a witness for no purpose other than to assist the defence in its endeavour to destroy the Crown's own case. No sensible rule of justice could require such a stance to be taken."
It would seem that the decision of the Senior Crown Prosecutor stated in the letter of 23 March 1989 not to disclose the two statements of Juke (the letter erroneously referred to "the statement") was taken having regard to paragraphs 2 and 6(ii) and (iii) of the Attorney-General's guidelines issued in 1982, 74 Cr. App. R. 302, 303:
"2. In all cases which are due to be committed for trial, all unused material should normally (i.e. subject to the discretionary exceptions mentioned in paragraph (6) be made available to the defence solicitor if it has some bearing on the offence(s) charged and the surrounding circumstances of the case.
"6. There is a discretion not to make disclosure--at least until counsel has considered and advised on the matter--in the following circumstances:
&dquo;(ii) The statement (e.g. from a relative or close friend of the accused) is believed to be wholly or partially untrue and might be of use in cross-examination if the witness should be called by the defence.
"(iii) The statement is favourable to the prosecution and believed to be substantially true but there are grounds for fearing that the witness, due to feelings of loyalty or fear, might give the defence solicitor a quite different, and false, story favourable to the defendant. If called as a defence witness upon the basis of this second account, the statement to the police can be of use in cross-examination."
As Steyn L.J. observed in delivering the judgment of the Court of Appeal in R. v. Winston Brown  Cr. App. R. 191, 196C these guidelines never constituted the law, they were merely a set of instructions to Crown Prosecution Service lawyers and prosecuting counsel.
The Decision of the Court of Appeal
On the appeal to the Court of Appeal a number of separate grounds were advanced on behalf of the appellants, all of which were rejected by that Court. One of the main grounds of appeal, in respect of which fresh medical and other evidence was heard by the Court of Appeal, was that there was a reasonable doubt whether the injuries inflicted on Wiltshire in the room in Conduit Street were a substantial cause of his death, and it was also submitted that there was a reasonable possibility that police officers had caused additional injuries to Wiltshire in the police station after he had been taken there from the hospital. This ground of appeal was rejected by the Court of Appeal which held that it was satisfied that the injuries sustained by Wiltshire in the room were a substantial cause of his death, and that the jury were right to reject the contention that the police had caused any injuries to him.
The Court of Appeal also rejected the ground that the conduct of a Detective Inspector in dissuading Juke from attending the committal proceedings gave rise to such an abuse of process that an appellant court should set aside the convictions. The Court of Appeal also rejected the further ground that the evidence of Kimberley Stadden was so unreliable as to render the convictions unsafe and the Court held that the jury were entitled to accept her evidence as that of a witness of truth.
In respect of the ground of appeal that the Crown had failed to provide to the defence copies of the two statements made by Juke to the police, the Court of Appeal considered Rex v. Bryant and Dickson 31 Cr.App.R. 146, Dallison v. Caffery  1 Q.B. 348, Regina v. Lawson 90 Cr.App.R. 107 and Regina v. Ward 96 Cr.App.R. 1 and Regina v. Winston Brown  Cr.App.R. 191 and then stated:
"If a witness is judged by the prosecutor to be incredible, does the overriding requirement for a fair trial require that witness should have access to his earlier statement which he may now regret? While the risks endorsed in Regina v. Lawson are sometimes lively ones, should the witness have the opportunity (if the first statement is true) of contriving an explanation of it which so far as possible avoids collision with his earlier words? Should a defendant be insulated against the risks attendant in all litigation of calling a witness who has given a statement to the opposing party.
"In our view, the answer is to be found in the judgment of this Court in Regina v. Lawson. The prosecutor has a discretion and good sense and experience will ordinarily safely point the way. Where it can be shown that an injustice has resulted from that exercise this Court will intervene, but in the case of the incredible witness the non-disclosure of a material statement is not per se an irregularity.
"Mr. Ian MacDonald QC, then leading counsel for both defendants, has since said that had he known of the actual contents of Juke's two statements, he would have called him, for Juke would have said that the contents of his second statement were untrue and only procured by police misinformation. While not questioning Mr. MacDonald's belief we have some reservations on the value of such reconstructions."
The Court of Appeal further observed on this ground of appeal that any prejudice from the non-disclosure of Juke's second statement was largely eliminated because the police questioning of Mills (which is set out in an earlier part of this judgment) revealed the substance of that statement to the defence.
Although the appellants had obtained copies of Juke's two statements to the police after the trial and before the hearing of the appeals, neither appellant applied to the Court of Appeal for leave to call Juke to give fresh evidence. However, the Court of Appeal itself decided (with the consent of the appellants) to call Juke to give evidence before it and the Court examined Juke and heard his evidence. Mr. Mansfield QC for the appellant Mills and Mr. Stewart QC for the appellant Poole declined the opportunity to cross-examine Juke, but he was cross-examined by Mr. Chadd Q.C. for the Crown.
After ruling that the failure by the Crown to give copies of Juke's police statements to the defence did not constitute an irregularity, the Court went on to state that even if the non-disclosure of Juke's statements had constituted a material irregularity, it was satisfied, having heard Juke's evidence, that the convictions were not unsafe.
The point of law of general public importance certified by the Court of Appeal was as follows:
"Where Prosecuting Counsel has reasonably decided that the maker of the statement is not a witness of truth and will seek to depart from or contrive an explanation for that statement if the witness is called, is the Prosecution's duty limited to furnishing the name and address of the witness only, or must Counsel provide copies of the statement to the Defence?"
The Common Law Rules Relating to Disclosure
In the present case the two statements which Juke made to the police were obviously highly material to the issues which arose because they described violence which took place in the room and related directly to issues of self defence and provocation. The principal argument advanced on behalf of the appellants by Mr. Mansfield QC was that the failure by the prosecution to give copies of the two statements to the defence constituted a material irregularity which rendered the convictions unsafe.
Prior to 1 January 1996 under section 2(1) of the Criminal Appeal Act 1968 the three grounds on which, subject to the operation of the proviso, the Court of Appeal was required to allow an appeal against conviction were:
" "(a) that the verdict of the jury should be set aside on the ground that under all the circumstances of the case it is unsafe or unsatisfactory; or
"(b) that the judgment of the court of trial should be set aside on the ground of a wrong decision of any question of law; or
"(c) that there was a material irregularity in the course of the trial,
"and in any other case shall dismiss the appeal:
"Provided that the Court may, notwithstanding that they are of opinion that the point raised in the appeal might be decided in favour of the appellant, dismiss the appeal if they consider that no miscarriage of justice has actually occurred."
A new section 2(1) was substituted by section 2 of the Criminal Appeal Act 1995 as follows:
"Subject to the provisions of this Act, the Court of Appeal--
"(a) shall allow an appeal against conviction if they think that the conviction is unsafe; and
"(b) shall dismiss such an appeal in any other case."
Accordingly since 1 January 1996 the sole ground for allowing an appeal has been that the conviction is unsafe, and there is no longer a proviso. However, notwithstanding that a material irregularity in the course of the trial is no longer a separate and statutory ground for allowing an appeal, it is still appropriate in a case such as the present to consider whether a failure to disclose constituted a material irregularity and, if so, whether the material irregularity has caused the conviction to be unsafe.
Before your Lordships the submissions advanced on behalf of the appellants and the Crown related principally to the issue whether, applying the present rules of the common law in respect of disclosure, the failure of the prosecution to furnish copies of Juke's statements to the defence constituted a material irregularity. But before turning to consider that issue it is necessary to address two preliminary questions. These questions arise because the trial of the appellants took place in 1990 before the present rules relating to disclosure were developed in a number of important cases. The first question is whether the failure to furnish the two statements constituted a material irregularity under the rules which were understood to apply in 1990. If the answer to this question is "No", the second question is whether your Lordships' House, hearing this appeal in 1997, should nevertheless apply the modern rules and consider whether the failure to disclose constituted a material irregularity under them.
The Court of Appeal in Ward, in the context of section 2(1) of the 1968 Act before it was amended by the 1995 Act, addressed this issue and stated at 643C:
"In his written submissions dealing with the appellant's complaints of non-disclosure, Mr. Langdale has distinguished between what, as a matter of law and procedure, was disclosable in 1974 and what is disclosable in 1992, but both he and Mr. Mansfield invited us to apply the standards of 1992 to the question of what ought to have been disclosed at the trial. We do not think that this is the correct approach to section 2(1)(c). It is true that in Regina v. Maguire  Q.B. 936, where the original trial had taken place in 1975, the court adopted a test for disclosability which first appeared in the Attorney-General's guidelines published in December 1981 (see Practice Note (Criminal Evidence: Unused Material  1 All E.R. 734), namely, whether the undisclosed material had 'some bearing on the offences(s) charged and the surrounding circumstances of the case.' The point does not, however, appear to have been argued--the case for the Crown was that non-disclosure was incapable of constituting a material irregularity in the course of the trial--and we do not regard Regina v. Maguire as requiring us to take what was called in argument a 'here and now' approach to the question of what should have been disclosed in 1974. The last 18 years have brought considerable advances in medical and forensic science.
"In deciding whether a verdict is "safe and satisfactory" for the purposes of section 2(1)(a), or whether there has been a miscarriage of justice for the purposes of the proviso, we must clearly take account of all of the knowledge and experience which is available to us in 1992, but in order to determine whether there were material irregularities in the course of the appellant's trial in 1974 we must, as it seems to us, apply as best we can the standards of what was considered to be proper and regular at that time. The distinction is, however, of limited practical significance because the appellant submits, and we accept, that even by the standards of 1974 there were failures to disclose by each of the four prosecution groups to which we have referred."
However I consider, with respect, that the distinction referred to by the Court of Appeal (which was of little practical significance in Ward's case) should not be adopted by Your Lordships. I am of this opinion because, as the Court of Appeal observed in Regina v. Maguire  1 Q.B. 936, 957D, a material irregularity which causes a conviction to be quashed is not a mere procedural irregularity and there is no real distinction between a material irregularity which causes a miscarriage of justice and a feature of the trial which causes a conviction to be unsafe, the Court of Appeal stating:
"The outcome of the debate as to whether non-disclosure of material is an irregularity within ground (c) or is a feature which can render a conviction unsafe or unsatisfactory under ground (a) has, as it seems to us, no consequence in regard to the result (as opposed to the route) of an appeal. This is because of the proviso. If the court is unable to hold 'that no miscarriage of justice has actually occurred' in a case of irregularity then, as in Regina v. Paraskeva, 76 Cr.App.R. 162, the conviction is not 'safe'. If it does so hold, then the court is effectively saying that the conviction is safe and satisfactory."
Therefore I am of the opinion that Your Lordships should apply the modern rules to determine whether the failure to disclose Juke's statements constituted a material irregularity. If it did, the further question then arises whether the irregularity caused the convictions to be unsafe.
The consideration of the prosecution's duty to make disclosure must commence with the judgment of the Court of Appeal delivered by Lord Goddard C.J. in 1946 in Rex v. Bryant and Dickson 31 Cr.App.R. 146. In that case a fraud took place in respect of the repairing of ambulances in a garage operated by a company in which the defendant Dickson was the major shareholder and where the defendant Bryant worked. The report stated the facts as follows:
"It was the duty of an employee of the company at the garage to make an estimate of the work which had to be done, and where that differed from the work specified in the note the sanction of a supervising mechanic named Campbell was required. The case was presented on the footing that Campbell, either consciously or unconsciously, facilitated the frauds which were perpetrated."
The prosecution had taken a statement from Campbell but they did not furnish a copy of the statement to the defence and they did not call Campbell as a witness at the trial. On the appeal it was argued that:
". . . the prosecution, having taken a statement from Campbell and having decided not to call him as a witness, were under a duty to furnish the defence with a copy of the statement, in order to enable the defendant to decide whether they should call him."
The argument was rejected by the Court of Appeal, Lord Goddard stating at p. 151:
"It is said that it was the duty of the prosecution to have supplied the defence with a statement which Campbell had admittedly made to the prosecution. The prosecution, for reasons which one can well understand, did not call Campbell. Is there a duty in such circumstances on the prosecution to supply a copy of the statement which they have taken to the defence? In the opinion of the Court there is no such duty, nor has there ever been. In the first place, if they had supplied a copy of the statement of Campbell, that would not have enabled the defence to put the statement in. The statement which Campbell made could have become evidence only if he had been called as a witness. But it is said that it was the duty of the prosecution to put that statement at the disposal of the defence. In the opinion of the Court, the duty of the prosecution in such a case is to make available to the defence a witness whom the prosecution know can, if he is called, give material evidence. That they did in this case, because when a letter was sent by the defence to the Director of Public Prosecutions, the reply of the Director of Public Prosecutions showed quite clearly that the prosecution did not intend to call him, but he added: 'There is no objection to your taking a statement from Campbell if you wish to do so'. That was said well before the trial. It was said after the close of the police court proceedings, when the defence knew that Campbell was not being called by the prosecution, and therefore could quite well themselves have gone to Campbell and taken a statement from him. Campbell was at the Court. Who brought him to the Court I do not know, nor is it material to inquire, but the defence could have called him if they had liked. No doubt Mr. Scott Henderson would not have been so unwise as to call him without having a statement from him, but if the defence did not choose to take a statement and find out what he was prepared to say, that is not a matter with which the prosecution are concerned. In the opinion of the Court it is quite wrong to say that it was the duty of the prosecution in these circumstances, having made Campbell available to the defence as a witness if they wished to call him, to go further and produce the statement which he had made."
In Dallison v. Caffery  1 Q.B. 348, 369A Lord Denning M.R. stated:
"The duty of a prosecuting counsel or solicitor, as I have always understood it, is this: if he knows of a credible witness who can speak to material facts which tend to show the prisoner to be innocent, he must either call that witness himself or make his statement available to the defence. It would be highly reprehensible to conceal from the court the evidence which such a witness can give. If the prosecuting counsel or solicitor knows, not of a credible witness, but a witness whom he does not accept as credible, he should tell the defence about him so that they can call him if they wish."
By drawing a distinction between making the statement of a credible witness available to the defence and telling the defence about a witness whom the prosecution do not accept as credible, it appears that Lord Denning was restating the practice formulated in Bryant and Dickson. I shall hereafter refer to this practice as "the rule in Bryant and Dickson".
The judgment of the Court of Appeal in Regina v. Lawson 90 Cr.App.R. 107 was delivered in June 1989 and in that case also the Court of Appeal accepted that the rule in Bryant and Dickson laid down the general practice, although it further stated that in some cases, including the case before it, an inflexible application of the rule could lead to injustice and there should be exceptions to it.
Therefore I consider that the non-disclosure of Juke's statements did not constitute a material irregularity applying the standards of what was considered to be proper in 1990.