Factual and Procedural Background
On 30th November 2006, the Appellant was convicted of sexual assault by penetration and sentenced to three years' imprisonment. The Appellant subsequently applied for leave to appeal out of time. After several preliminary hearings, the appeal court granted leave to appeal on the basis of fresh evidence in the form of an expert report related to DNA evidence presented at the original trial, which took place at Kingston Crown Court before Her Honour Judge Barnes.
The complainant, a 16-year-old female referred to as the complainant, attended a party at a house where the Appellant, an older male, lived. During the evening, after consuming a significant amount of alcohol, the complainant became unwell and stayed overnight at the house. The Appellant assisted her to her bedroom and later allegedly sexually assaulted her by digitally penetrating her vagina, causing injuries consistent with such an assault. The Appellant denied the sexual assault but confirmed helping the complainant when she was sick.
At trial, expert evidence included a medical examination confirming injuries consistent with non-accidental blunt penetration, toxicology evidence, and DNA evidence obtained from the Appellant's fingernail clippings. The DNA profile showed a major profile matching the Appellant and a minor full profile matching the complainant on the left hand, with a match probability exceeding one billion to one. There was agreement that the DNA was the complainant's but disagreement over the evaluation of the possibilities of how the DNA was transferred.
Legal Issues Presented
- Whether fresh evidence demonstrates that the DNA evidence presented at trial was not sufficiently reliable to allow experts to evaluate the possibilities of DNA transfer.
- Whether expert evidence relating to scientific research and experience not published in scientific papers can be properly considered in evaluating DNA evidence.
- Whether the procedures under Part 33 of the Criminal Procedure Rules, relating to expert evidence, were sufficiently followed, and the implications of any failure to do so.
Arguments of the Parties
Appellant's Arguments
- The fresh expert evidence submitted shows there was no reliable scientific basis at the time of trial for experts to evaluate the possibilities of DNA transfer.
- The evaluation evidence should not have been admitted because the scientific certainty and reliability required for such an opinion did not exist.
- The expert evidence relied upon by the Crown was not properly supported by published scientific research, and reliance on unpublished evidence or practical experience was inappropriate.
Respondent's Arguments
- The Crown's expert and the defence expert at trial were both highly qualified and experienced in DNA forensic science.
- Scientific research, including unpublished studies and practical experience, provided a sufficiently reliable basis for expert evaluation of the DNA transfer possibilities.
- Practical experience and unpublished evidence are a legitimate and necessary part of expert evidence, particularly in forensic science, where not all relevant knowledge is contained in published papers.
- The Appellant received a fair trial, and the evaluation evidence was logically and scientifically sound.
Table of Precedents Cited
| Precedent |
Rule or Principle Cited For |
Application by the Court |
| Reed and Reed [2009] EWCA Crim 2698 |
Importance of strict adherence to Part 33 of the Criminal Procedure Rules for expert evidence; necessity of detailed consideration and refinement of issues in DNA cases |
The court emphasized that the evaluation of DNA transfer possibilities must be carefully isolated and presented as agreed expert evidence to the jury, referencing Reed and Reed for legal principles on expert evidence and evaluation. |
| R v Abadom 76 Cr.App.R 48 |
Permissibility of experts relying on the work of others as part of their opinion |
The court cited this precedent to support the principle that experts may rely on unpublished work or others' research, provided the basis of their opinion is disclosed and open to challenge. |
Court's Reasoning and Analysis
The court began by acknowledging the fundamental importance of strict compliance with Part 33 of the Criminal Procedure Rules regarding expert evidence, highlighting that proper isolation and agreement of expert issues would have streamlined the trial process.
It was common ground that the DNA profiles were correctly obtained and that the complainant's DNA was present on the Appellant's left hand. The central dispute concerned the evaluation of how the DNA was transferred, with several possible mechanisms identified, including primary and secondary transfer.
The court considered the qualifications and experience of the experts involved. The trial experts were both highly qualified and experienced, with the defence expert notably possessing extensive practical experience in forensic DNA science. The fresh evidence was primarily based on reports by a scholar with strong academic credentials but lacking practical forensic experience.
The court examined the scientific studies, including both published and unpublished papers, and practical experience evidence. It found that reliance solely on published papers without practical experience was insufficient to challenge the trial experts' evaluations. The unpublished research and day-to-day forensic experience provided a reliable scientific basis for evaluating DNA transfer possibilities.
Regarding the specific scientific issues, the court noted consensus between experts on the relative ease or difficulty of DNA transfer from various sources and the richness of the vaginal DNA source. It found that the scientific evidence supported the possibility of expert evaluation in this case.
The court also addressed the admissibility of unpublished evidence and practical experience, endorsing the principle that experts may rely on such material, provided it is disclosed and subject to cross-examination. The court emphasized the importance of practical experience in forensic science, which may not always be captured in published literature.
Ultimately, the court concluded there was no fresh evidence undermining the reliability of the expert evaluation given at trial, and that the Appellant had received a fair trial. The DNA evidence, while described as a makeweight, conclusively supported the jury's verdict.
Holding and Implications
The appeal is DISMISSED.
The court upheld the original conviction, finding no new reliable evidence to challenge the expert evaluation of the DNA evidence. The decision confirms the acceptability of expert evidence based on a combination of published research and practical forensic experience, reinforcing the importance of procedural compliance with expert evidence rules. No new precedent was established beyond affirming existing principles regarding expert evidence in DNA cases. The direct effect is the maintenance of the Appellant's conviction and sentence.