Law Report: Convict's evidence was admissible / Chan v The Queen. Privy Council (Lord Keith of Kinkel, Lord Mustill, Lord Woolf, Lord Lloyd of Berwick and Lord Nicholls of Birkenhead), 13 December 1994.

The fact that a murder-trial witness had come forward and given evidence in the hope of receiving a lighter sentence for an unrelated offence of which he had just been convicted, did not render his evidence inadmissible, provided the jury was warn ed of its potential fallibility.

The Privy Council dismissed an appeal by Chan Wai-Keung from the decision of the Hong KongCourt of Appeal upholding his conviction for murder.

Part of the evidence against him at his trial came from a witness, Yip Wai-Sheung, to whom the defendant was said to have confessed the murder. At the time he gave the evidence, Mr Yip had just been convicted for an unrelated offence of drug trafficking and was awaiting sentence. He was encouraged to give evidence by being given immunity from prosecution for offences in which he might incriminate himself by his testimony, and by the expectation of lighter treatment when sentenced in the drugs case.

The appellant complained that (1) the calling of Mr Yip in these circumstances was so objectionable in principle that a conviction founded on his evidence could not be allowed to stand; and (2) even if not objectionable in principle, the way the evidencewas obtained in this case took it over the line. Mr Yip had so much of an incentive for making up a false story that the jury could not safely rely on his evidence, it was said.

Martin Thomas QC and Gordon Wignall (Edwin Coe) for the appellant; Grenville Cross QC, Deputy DPP, and Cheung Wai-Sun, both of the Hong Kong Bar, for the Crown.

LORD MUSTILL said the question of principle involved consideration of distinct lines of authority on the treatment of co-accused and accomplices. First, as to sentencing, although the decision whether to sentence before or after the trial of a co-accusedremained within the judge's discretion, it was now usually thought better for the same judge to sentence all the accused at the end of the trial, when he could best form an impression of their relative culpability and avoid discrepancies.

A second line of authority had long recognised the benefits of allowing one accused to turn Queen's evidence and obtain an immunity from further process or a discount from sentence by giving evidence against another. Where the witness was under threat ofprosecution or sentence for offences other than that for which the accused was being tried, the benefit to the public interest of having criminals detected and punished, and the risk of perjured evidence being given under an inducement was just the sameas where one co-accused gave evidence against another.

How should the two lines be drawn together? The discretion still remained whether to sentence the witness at the beginning or end of the accused's or co-accused's trial. But here there was no question of disparity of sentence between co-accused since theoffences were wholly unconnected.

Assuming the prosecution honoured the promise made to Mr Yip, to put the fact of his assistance before the relevant court, as it had in fact done, the credit for giving evidence had already been accorded to Mr Yip whether he was sentenced before or afterMr Chan's trial. The inducement might have been less cogent in the former case, but the principle was the same.

Once the courts had taken the large step of recognising that circumstances might justify the calling of a witness who stood to gain by giving false evidence, it became impossible to say that what happened in this case was necessarily contrary to the proper conduct of the murder trial. What was required was that the potential fallibility of Mr Yip's evidence should be put squarely before the jury, and that had been done.

For these and other reasons, Mr Chan's appeal was dismissed.