Hedges, R. v

Factual and Procedural Background

On 13 November 2023, at the Crown Court at Maidstone before Judge Cavanagh and a jury, the Applicant was convicted of the murder of her son, an 18-month-old child, who died on 28 November 2020. The Applicant's partner was also convicted of the same murder at the same trial. The events leading to the child's death occurred overnight in a caravan occupied only by the Applicant and her partner. The child was last seen alive in the early evening of 27 November 2020 and was found dead the following morning. Medical examination revealed multiple injuries and fractures sustained shortly before death, with the cause of death recorded as "unascertained - unnatural causes." Forensic analysis identified probable and possible bite marks on the child's body, which became a significant element of the prosecution's case.

On 2 July 2025, the court heard a renewed application for leave to appeal against the Applicant’s conviction, focusing on the admissibility of expert forensic odontology evidence regarding bite marks. The court reviewed detailed submissions and the trial judge’s reasons for admitting the expert evidence. The court concluded that the judge’s decision was sound and refused leave to appeal, providing observations for potential future cases involving similar issues.

Legal Issues Presented

1. Whether expert forensic odontology evidence relating to bite marks is admissible in criminal proceedings.
2. Whether the specific expert evidence given by the forensic odontologist in this case was sufficiently reliable and the expert competent to give that opinion.
3. Whether the Applicant’s conviction was unsafe given the contested bite mark evidence.

Arguments of the Parties

Appellant's Arguments

• The forensic odontology evidence is not suitably regulated or scientifically validated to be admitted at trial.
• The field lacks formal regulation by the Forensic Science Regulator and specific prosecutorial guidance.
• The British Association of Forensic Odontologists does not adequately evaluate its members’ performance.
• There was no peer review of the expert’s work in this case.
• Scientific literature and expert testimony (notably from Professor Pretty) cast doubt on the reliability of bite mark evidence, citing past miscarriages of justice and methodological flaws.
• The trial judge was wrong to dismiss challenges to the reliability of the bite mark evidence.

Respondent's Arguments

• The forensic odontologist called by the prosecution is highly qualified, experienced, and gave evidence consistent with current scientific understanding.
• The opposing expert did not examine the specific evidence in this case and lacked recent practical experience.
• The expert evidence was relevant and carefully limited to excluding or not excluding individuals rather than making positive identifications.
• The scientific reports relied upon by the appellant had limited applicability or were mischaracterized, particularly regarding the uniqueness of dentition.
• Forensic odontology evidence remains admissible in the United States and elsewhere, reflecting ongoing acceptance of the field with appropriate limitations.
• The expert’s approach was cautious, avoided overstating conclusions, and followed established good practice.

Table of Precedents Cited

Court's Reasoning and Analysis

The court applied the test for admissibility of expert opinion evidence as set out in Criminal Practice Direction 7.1.1, requiring relevance, necessity, competence, and sufficient reliability. It was undisputed that the evidence was relevant and necessary, focusing the analysis on competence and reliability.

The court acknowledged concerns raised by the appellant’s expert about the scientific basis of bite mark evidence, particularly criticisms rooted in historical miscarriages of justice in the United States and challenges to the uniqueness of dentition. However, the court noted that the prosecution’s expert expressly rejected making positive identifications based solely on bite mark comparison, aligning with modern scientific consensus.

The court reviewed contemporary scientific literature indicating that forensic odontology now recognizes limitations in bite mark analysis, including the inability to claim uniqueness or make definitive identifications, and that many bite patterns do not contain sufficient information for conclusive analysis.

The court found that the appellant’s expert failed to engage with relevant recent literature supporting a more cautious and scientifically grounded approach. The court accepted that bite mark evidence, when presented with appropriate qualifications and limitations, remains sufficiently reliable for expert opinion.

Regarding the expert’s competence, the court found the prosecution’s expert to be highly qualified, experienced, and careful in his methodology. The expert acknowledged the limitations of photographic analysis and skin elasticity, did not overstate his conclusions, and appropriately limited his opinion to including or excluding potential biters rather than positive identification.

The court also noted the absence of peer review of the expert’s reports but recognized this as one factor among many in assessing admissibility. The defense did not call evidence at trial to counter the expert’s methodology or conclusions.

Finally, the court emphasized the strength of the overall case against the Applicant, noting that the bite mark evidence was not the sole basis for conviction but part of a broader evidential context establishing responsibility for the fatal injuries.

Holding and Implications

The court REFUSED LEAVE TO APPEAL against the Applicant’s conviction.

The direct effect of this decision is that the conviction stands and the expert forensic odontology evidence admitted at trial is upheld as admissible and reliable within the limits discussed. The court’s judgment provides guidance on the admissibility and evaluation of bite mark evidence in future cases but does not establish new binding precedent beyond affirming existing principles of expert evidence admissibility.