R v Justin Plummer

Fresh expert evidence should generally be admitted where it is credible and fresh, unless it could have no effect on the safety of the conviction. Credible evidence that is not fresh should be admitted where exclusion would risk a miscarriage of justice.

Where prosecution experts gave evidence outside their expertise or used unsuitable methods, and that evidence materially influenced the conviction, the conviction may be unsafe. A retrial may nevertheless be ordered where the offence is grave, a credible case remains, and a fair trial is possible after balancing the public interest against the defendant’s legitimate interests.

The appellant was convicted in 1998 of murdering Janice Cartwright-Gilbert during an alleged burglary, together with numerous burglary and other offences. His conviction had previously been refused leave to appeal, but the Criminal Cases Review Commission referred the case back to the Court of Appeal after obtaining fresh expert reports on footwear-mark evidence.

The fresh evidence criticised the trial methods used by prosecution experts and rejected their conclusion that the appellant’s trainer had conclusively caused marks on the victim’s face. The Crown accepted that material parts of the expert evidence were erroneous. The court therefore had to decide whether the fresh evidence should be admitted, whether the murder conviction was safe, and whether a retrial was in the interests of justice after approximately 23 years.

1. Fresh evidence. The court granted the application under the Criminal Appeal Act 1968, section 23. It adopted the sequential approach in R v Lundy [2013] UKPC 23: credibility is considered first; if the evidence is credible, freshness and the possibility of obtaining it with reasonable diligence are addressed; credible and fresh evidence should generally be admitted unless it could have no effect on the safety of the conviction; and credible but not fresh evidence should be admitted where exclusion risks a miscarriage of justice.
2. Safety of conviction. The fresh evidence was credible and exposed serious defects in the prosecution footwear analysis. Dr Lewin’s technique was neither validated nor suitable for footwear comparisons, and Professor Vanezis had also given evidence outside the proper scope of his expertise. Their evidence had been central to the jury’s assessment of the footwear mark. The Crown’s concessions, together with the evidence of Lee Parkes, showed that the conviction was unsafe.
3. Disposition of appeal. The appeal was allowed and the murder conviction was quashed. The court did not determine the admissibility of every item of evidence at a future trial, leaving those questions to the trial judge.
4. Retrial. Under section 7 of the Criminal Appeal Act 1968, the question was whether a retrial was in the interests of justice. Applying R v Graham [1997] 1 Cr.App.R 302, the court balanced the public interest in prosecuting a person reasonably suspected on available evidence of serious crime against the defendant’s legitimate interests, including delay, punishment already undergone, unfairness and oppression.
5. The remaining evidence provided at least a credible case, and the court considered that a fair trial remained possible despite the age of the allegation, lost exhibits, deceased witnesses and the appellant’s period in custody. A retrial was therefore ordered. The appellant was to be arraigned on the murder count and two common-assault counts, with joinder left to the trial judge. Publication of the judgment was postponed until the retrial concluded.

• Crown Court at St Albans: The appellant was convicted of murder on 16 December 1998 and sentenced to life imprisonment with a minimum term of 16 years.
• Court of Appeal (Criminal Division): Leave to appeal was refused by the single judge on 23 September 1999 and by the full court on 17 January 2000. Following a successful Criminal Cases Review Commission referral, the present court admitted fresh evidence, allowed the appeal, quashed the conviction and ordered a retrial.