Can Bite Mark Evidence Be Used in Criminal Trials in the UK?

What Is Bite Mark Evidence?

Bite mark evidence arises when investigators believe a suspect may have left a dental impression on a victim’s skin or on an object at the scene of an alleged offence. 

Specialists in forensic dentistry may analyse these marks by comparing them with dental impressions taken from a suspect.  

This process may involve: 

• photographing the suspected bite mark 
• creating dental impressions of a suspect’s teeth 
• comparing the shape and spacing of teeth 
• analysing patterns such as missing or damaged teeth 

Historically, investigators sometimes assumed that dental patterns were unique to each individual, similar to fingerprints. However, modern research has challenged this assumption. 

How Bite Mark Analysis Is Used in Criminal Investigations

Bite marks may be examined when an alleged offence involves physical contact or violence. 

Examples include: 

• assaults 
• sexual offences 
• murder investigations 
• cases involving defensive injuries 

Marks may appear on: 

• the victim’s skin 
• the suspect 
• objects at the scene of a crime 

A forensic odontologist may attempt to determine whether a suspect could have caused the mark by comparing dental impressions with photographs or casts of the injury. 

However, the process is often highly subjective and dependent on expert interpretation.

How UK Courts Assess the Reliability of Forensic Evidence

Courts in England and Wales carefully assess expert evidence presented in criminal trials. 

The court must determine whether the evidence: 

• is based on recognised scientific principles 
• has a reliable methodology 
• assists the jury in determining the facts 

Judges have the authority to exclude unreliable evidence where its probative value is outweighed by the risk of unfair prejudice. 

The legal framework governing expert evidence can be found in the Criminal Procedure Rules, which regulate how expert witnesses present opinions in criminal proceedings. 

Where forensic evidence lacks strong scientific support, it may be challenged by the defence and subjected to rigorous scrutiny during cross-examination. 

How Criminal Defence Solicitors Challenge Bite Mark Evidence

When forensic evidence forms part of the prosecution case, defence lawyers will examine it in detail. 

Potential defence strategies may include: 

Challenging the Expert Methodology

Defence solicitors may question whether the forensic techniques used were scientifically reliable or widely accepted. 

Highlighting Scientific Uncertainty

Experts may disagree about whether bite marks can uniquely identify a person. Demonstrating this uncertainty can weaken the prosecution’s case. 

Presenting Alternative Expert Evidence

In some cases, defence teams may instruct independent forensic experts to review the analysis. 

These experts may challenge: 

• the accuracy of the comparison 
• the quality of photographs or impressions 
• the assumptions made by the prosecution expert. 

Cross-Examining the Prosecution Expert

During trial, defence advocates may test the expert’s conclusions by exploring: 

• limitations in the analysis 
• potential bias 
• alternative explanations for the mark. 

This scrutiny can significantly reduce the weight a jury gives to forensic bite mark evidence.

What To Do If Forensic Evidence Is Being Used Against You

If forensic evidence is central to a criminal allegation, obtaining legal advice at an early stage is critical. 

A solicitor can: 

• review the prosecution’s forensic evidence 
• identify weaknesses in expert analysis 
• instruct independent forensic specialists 
• develop a defence strategy tailored to the case. 

In cases involving controversial forms of forensic identification, such as bite mark analysis, careful legal scrutiny can be essential. 

If you are facing allegations where forensic evidence may play a role, speaking to an experienced criminal defence solicitor can help you understand your legal position and the options available to you.