In general, adducing fresh evidence in the Court of Appeal is difficult. In Erskine  2 Cr App R 29 the court said that the decision whether to admit fresh evidence pursuant to section 23 of the Criminal Appeal Act 1968 is case and fact specific; the discretion to receive such evidence is a wide one focussing on the interests of justice, with the considerations listed in section 23(2)(a) to (d) being matters that require specific attention, but being neither exhaustive nor conclusive; the fact that the issue to which the fresh evidence relates was not raised at trial does not automatically preclude its reception; however, it is clear from the statutory structure, as explained in the authorities, that unless a reasonable and persuasive explanation for the omission is offered, it is highly unlikely that the “interests of justice” test will be satisfied.
In relation to expert evidence, in Jones (Steven)  1 Cr.App.R. 86, the Court of Appeal considered the issue in the context of the amendments to section 23 enacted by the 1995 Act. Such evidence is admissible on appeal, but section 23(2)(d) acknowledges the crucial obligation on a defendant to advance his whole defence before the jury. There would rarely be a reasonable explanation for failure to call such evidence at trial, for expert witnesses were interchangeable in a way that factual witnesses were not (as to which, see also Lomas, 53 Cr.App.R. 256). It would subvert the trial process if a defendant were to be generally free to mount on appeal an expert case which, if sound, could and should have been advanced before the jury. To similar effect, see Cleobury  Crim.L.R. 615, CA, in which the court emphasised that it is not its function to permit expert evidence to be re-litigated on appeal.
The Privy Council considered the impact of fresh expert evidence on appeal in Lundy v The Queen  UKPC 28.
Mr Lundy was convicted of murdering his wife and daughter Amber in Palmerston North, New Zealand in 2002. They were found hacked to death in their home on the 30th August 2000. Mr Lundy was in Petone, 145km south of Palmerston, either side of the time that the prosecution alleged the murder took place. Time of death was thus crucial. There were no eye-witnesses and expert evidence played a central part.
There were three main strands to the Crown’s case that were crucial to the trial. Each of these was challenged by new evidence which, according to submissions made on Mr Lundy’s behalf to the Board, showed that there had been a miscarriage of justice. The expert evidence was as follows:
- The contents of Mrs Lundy and Amber’s stomachs showed that they must have died at around 7 p.m.;
- Biological tissue on Mr Lundy’s shirt was central nervous system (C.N.S.) tissue from Mrs Lundy, and Mr Lundy’s lawyer had conceded that this was the case.
- Although the Lundys’ computer showed it had been switched off at 10.52 p.m. that night, computer experts claimed that the disordered state of some of its registry files suggested that the settings had been tampered with in order to disguise when it had in fact been shut down.
The Board had to decide two principal issues:
1. Was Mr Lundy entitled to introduce the new evidence?
2. If so, what was its significance in the appeal?
The Board did not have to decide (nor did it purport to do so) whether the new evidence that Mr Lundy wanted to introduce was better or more accurate than the prosecution’s evidence (paragraph 127). It held, first of all, that new evidence can be admitted only if it is credible. It would also usually have to be ‘fresh’ evidence: evidence that the defendant or his lawyers could not have obtained for the trial if they had been reasonably diligent. If both those conditions are met, the evidence would be admitted unless it would not affect the safety of the conviction. But if it were credible evidence that was not ‘fresh’ it could still be admitted if there was a risk of a miscarriage of justice (paragraph 120. Where a case against an accused rests exclusively or principally on scientific evidence, when on an appeal, application is made to have admitted new scientific material which presents a significant challenge to that evidence, the court should not be astute to exclude the new material solely because it might have been obtained before the trial (paragraphs 121-122).
The new evidence in this case clearly was credible: the experts who provided it were distinguished in their fields, and it was certainly capable of being believed. Although the evidence was not ‘fresh’ in the technical sense defined above, the Board admitted it because it ‘presents a direct and plausible challenge to a central element of the prosecution case’ and there was therefore a risk of a miscarriage of justice. A retrial was ordered.
Although, of course, strictly speaking Privy Council decisions are only of persuasive force in England and Wales, this decision is of considerable significance to those who have been convicted of serious offences based on scientific evidence.
The full judgment in Lundy can be found here.
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