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

What Is Bite Mark Evidence?

Bite mark evidence may arise where investigators believe a mark on a person’s skin, clothing, or an object could have been caused by human teeth.

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, some bite mark evidence was treated as if dental patterns could identify a person in a similar way to fingerprints. That approach is now treated with significant caution.

How Bite Mark Analysis Is Used in Criminal Investigations

Bite mark evidence may be considered in cases involving alleged violence, physical contact, or defensive injuries.

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 consider whether a mark is a possible or probable bite mark and whether a suspect can be included or excluded as a possible source.

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 

The court may consider factors such as the expert’s qualifications, the quality of the data, the method used, whether the work has been peer reviewed and whether the opinion has been fairly stated.

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 bite mark evidence is used, the court may look closely at whether the expert is offering a limited and cautious opinion, or whether they are making a stronger claim than the science can support.

How Criminal Defence Solicitors Challenge Bite Mark Evidence

Where bite mark evidence forms part of the prosecution case, the defence should examine it carefully.

Potential defence strategies may include: 

Challenging the Expert Methodology

The defence may question whether the expert used a reliable and accepted method.

Highlighting Scientific Uncertainty

The defence may challenge any suggestion that bite mark evidence can identify a person with certainty.

If the science only supports a limited conclusion, the jury should understand that limitation clearly.

Presenting Alternative Expert Evidence

In some cases, the defence may instruct an independent forensic odontologist or other expert to review the prosecution evidence.

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 can affect how much weight the court or jury gives to the evidence.

What To Do If Forensic Evidence Is Being Used Against You

If forensic evidence is part of the allegation, legal advice should be sought as early as possible.

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 bite mark analysis, careful review is particularly important because the evidence may be technical, subjective and open to challenge.

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.