ABSTRACT
That leaves the following matters: should questions be permitted as to: (1) complaints by members of the public about the behaviour of the witness on other occasions not yet adjudicated upon by the Police Complaints Authority; (2) discreditable conduct by other officers in the same squad; (3) other cases in which the witness has given evidence which have resulted in acquittal of the defendant at the trial or the quashing of the conviction on appeal. This is an area where it is impossible and would be unwise to lay down hard and fast rules as to how the court should exercise its discretion. The objective must be to present to the jury as far as possible a fair, balanced picture of the witnesses’ reliability, bearing in mind on the one hand the importance of eliciting facts which may show, if it be the case, that the police officer is not the truthful person he represents himself to be, but bearing in mind on the other hand the fact that a multiplicity of complaints may indicate no more than what was described before us as the ‘bandwagon’ effect. We do not consider that it would have been proper to suggest to the officer in the present case that he had committed perjury or any other criminal offence by putting to him that he had been charged but not yet tried. Nor do we think that complaints to the Police Complaints Authority which have not been adjudicated upon would properly be the subject of cross-examination. It would not be proper to direct questions to an officer about allegedly discreditable conduct of other officers, whether or not they happened to be serving in the same squad. There remains the problem of other cases in which the witness has, so to speak, unsuccessfully given evidence. We have the advantage in this respect of earlier decisions of this court. In Reg v Thorne (John) (1977) the judge at trial had refused an application by the defence to have a police officer recalled for further cross-examination about verdicts of acquittal which had been returned by other juries in other cases in which he had been involved. Lawton LJ in the course of giving judgment said, at p 15: ‘The fact that [the police officer] may have given evidence against other accused in other cases which did not lead to convictions, did not begin to prove that he was biased against any of the appellants in this case in any sense known to the law of evidence. The fact that a jury returns a verdict of not guilty does not go to prove that an important witness for the prosecution, albeit the sole witness, is a liar.’ The matter was further considered in Reg v Cooke (Gary) (1986) in which the earlier authorities, including Reg v Thorne (John), were considered. The facts in the case were these. A police officer had allegedly obtained admissions in interviews with a number of different accused persons about the same group of offences. The interviews were part of a connected series which took place over a short period of time. The various accused persons were not all tried together. Two of the other defendants were acquitted. The evidence against them had consisted almost entirely of admissions said to have been made by them to a police officer as to whose evidence the jury must plainly have had doubt. At the trial evidence was given by the same police officer of admissions allegedly made by Cooke. The trial judge refused leave to cross-examine the police officer about the circumstances of the acquittal of the other accused persons. Upon appeal Parker LJ, giving the judgment of the court, said, at pp 291-292: ‘It seems to us that where a police officer has allegedly obtained admissions on interviews about the same group of offences from different accused as part of a connected series of interviews over a short period, where those interviews are alleged to have been fabricated, and where the alleged admissions were the
essential evidence against one or more of the accused who were nevertheless acquitted, justice demands that the jury should know this when they are considering a challenge by another accused to the truth of evidence of admissions said to have been made by him to the same officer at about the same time and about the same series of events.’ There it was the behaviour of the officer in what was to all intents and purposes the same case as that being tried which was the subject of the proposed crossexamination. That was therefore a limited extension of the principle expressed in Reg v Thorne (John). The result of those two decisions seems to be this. The acquittal of a defendant in case A, where the prosecution case depended largely or entirely upon the evidence of a police officer, does not normally render that officer liable to crossexamination as to credit in case B. But where a police officer, who has allegedly fabricated an admission in case B, has also given evidence of an admission in case A, where there was an acquittal by virtue of which his evidence is demonstrated to have been disbelieved, it is proper that the jury in case B should be made aware of that fact. However, where the acquittal in case A does not necessarily indicate that the jury disbelieved the officer, such cross-examination should not be allowed. In such a case the verdict of not guilty may mean no more than that the jury entertains some doubt about the prosecution case, not necessarily that they believed any witness was lying ...20
