First Published: 28th of October, 2026 | Last Updated: 29th of October, 2026
Forensic expert evidence can play a significant role in criminal proceedings, helping courts understand technical matters that fall outside ordinary knowledge. However, when instructing a forensic expert, solicitors and barristers may be uncertain about the importance of accreditation and whether it is a legal requirement.
In England and Wales, forensic science is subject to a regulatory framework intended to support the reliability of evidence presented within the criminal justice system. This includes accreditation to international standards, such as ISO/IEC 17025, and compliance with the Forensic Science Regulator's Codes of Practice.
However, not all forensic experts are accredited, and not all forensic activities are subject to the same regulatory requirements.
Understanding these distinctions can help legal teams make informed decisions when instructing forensic experts and assessing evidence provided by other parties.
What Is ISO/IEC 17025 Accreditation?
ISO/IEC 17025 is an internationally recognised standard specifying requirements for the competence, impartiality and consistent operation of testing and calibration laboratories.
In the United Kingdom, accreditation to ISO/IEC 17025 is provided by the United Kingdom Accreditation Service (UKAS), which independently assesses laboratories against the requirements of the standard.
For forensic laboratories, accreditation provides independent assurance that appropriate systems and procedures are in place to support technically valid results.
These include:
Personnel competence: Ensuring that individuals performing forensic examinations have the appropriate knowledge, skills, training and demonstrated competence.
Method validation: Establishing that examination methods are suitable for their intended purposes and perform within understood limitations.
Equipment management: Ensuring that equipment and software used during examinations are suitable, appropriately maintained and subject to relevant checks.
Quality assurance: Monitoring the validity of results through appropriate quality control activities.
Impartiality: Identifying and managing risks that could compromise the objectivity of forensic examinations.
Technical records: Maintaining sufficient documentation to support the traceability and review of forensic work.
Accreditation is not simply an assessment of an individual expert's qualifications. It involves independent evaluation of the laboratory's technical activities and the systems supporting them.
Importantly, accreditation applies only to the activities included within a laboratory's accredited scope, rather than automatically covering every service the organisation provides.
What Are the Forensic Science Regulator's Codes of Practice?
The Forensic Science Regulator's Codes of Practice establish statutory quality requirements for specified forensic science activities undertaken in connection with the criminal justice system in England and Wales.
The Codes were introduced under the Forensic Science Regulator Act 2021, with the current version, Version 2, coming into force on 2 October 2025.
They build upon international standards, including ISO/IEC 17025, by introducing additional requirements applicable to forensic science.
Depending on the forensic science activity, these requirements may address areas such as:
The validation and verification of forensic methods.
The competence and authorisation of forensic practitioners.
The management, handling and examination of exhibits.
The interpretation and reporting of forensic findings.
The review and quality assurance of forensic examinations.
The declaration of compliance or non-compliance with the Codes.
The Codes define which forensic science activities are subject to their requirements, including circumstances in which accreditation is necessary.
Consequently, accreditation to ISO/IEC 17025 does not automatically demonstrate compliance with the Codes of Practice.
Where the Codes require accreditation that incorporates their requirements, a laboratory accredited solely to ISO/IEC 17025 would not meet that particular compliance requirement.
Does a Forensic Expert Have to Be Accredited?
There is no universal requirement for every forensic expert providing evidence in criminal proceedings to hold accreditation.
Whether accreditation is required depends on the nature of the forensic activity being undertaken and the requirements applicable to that activity.
The Forensic Science Regulator's Codes of Practice identify specific forensic science activities for which compliance is required. For some of these activities, the requirements include accreditation to an appropriate international standard.
Other forensic examinations may fall outside the activities covered by the statutory Codes, or may be subject to different requirements.
It is therefore important to distinguish between three separate matters:
Expert competence: Whether an individual possesses the knowledge, experience and expertise necessary to undertake the examination and provide an informed opinion.
Laboratory accreditation: Whether the organisation has been independently assessed against a recognised standard for the relevant technical activity.
Regulatory compliance: Whether the forensic examination has been performed in accordance with the applicable requirements of the Forensic Science Regulator's Codes of Practice.
Although these matters are related, they are not interchangeable.
An experienced forensic practitioner may be capable of providing reliable expert evidence without working within an accredited laboratory. Equally, accreditation does not guarantee that every conclusion reached by an expert will be correct.
Can Evidence from an Unaccredited Forensic Expert Be Used in Court?
Yes. The absence of accreditation does not automatically make forensic evidence inadmissible.
Under Section 4 of the Forensic Science Regulator Act 2021, a court may take into account a failure to comply with the statutory Codes of Practice when determining matters arising during proceedings.
However, the Act does not establish a general rule that evidence produced without the required compliance must be excluded.
The Crown Prosecution Service similarly recognises that forensic evidence which does not comply with the Codes may still be reliable. Such evidence may require closer scrutiny, with the courts determining its admissibility and the weight to be attached to it on a case-by-case basis.
For solicitors and barristers, the important question is therefore not simply whether an expert is accredited, but whether the examination was undertaken using reliable methods and appropriate safeguards.
Where an examination falls within an activity requiring compliance with the Codes, any non-compliance should be appropriately declared and explained.
This allows legal teams to consider the significance of the non-compliance, including any measures taken to mitigate potential risks to the reliability of the findings.
Why Does Accreditation Matter When Instructing a Forensic Expert?
Forensic examinations frequently involve technical decisions that are not immediately apparent from the conclusions presented in an expert report.
For example, a forensic video examination may involve selecting processing techniques, assessing the suitability of source material and determining whether the available imagery supports a particular interpretation.
The reliability of the resulting opinion depends not only on the experience of the examiner, but also on the suitability of the methods employed and the procedures used to evaluate the findings.
An accredited laboratory is subject to independent assessment of the technical activities within its scope. This provides additional assurance that appropriate procedures exist to manage factors capable of affecting the reliability of results.
Nevertheless, accreditation should not be treated as a substitute for critically examining the expert's methodology, assumptions and conclusions.
Practical Example of Why Accreditation and Compliance Matter
The following hypothetical example illustrates how accreditation and regulatory compliance may be relevant when considering multimedia forensic evidence.
Example: Enhancement of Poor-Quality CCTV Evidence
A solicitor instructs a forensic laboratory to enhance CCTV footage in an attempt to clarify the actions of an individual.
The laboratory applies several processing techniques, resulting in an image that appears substantially clearer than the original.
However, the enhanced imagery contains visual features that were not clearly distinguishable in the source recording.
Without appropriate validation and quality assurance, there is a risk that processing artefacts may be mistaken for genuine scene information.
An appropriately validated forensic enhancement methodology, together with suitable examination and review procedures, can help manage these risks.
Accreditation provides independent assurance concerning the laboratory's implementation of such procedures where the activity falls within its accredited scope.
How Can Solicitors Verify a Forensic Laboratory's Accreditation?
Before instructing a forensic expert, legal teams can take several steps to establish the accreditation status of the organisation undertaking the work.
A useful starting point is the UKAS website, which provides publicly accessible information about accredited organisations.
Each accredited laboratory has a schedule identifying the activities covered by its accreditation.
Solicitors should consider:
Whether the laboratory holds current UKAS accreditation.
Whether the proposed forensic examination falls within its accredited scope.
Whether the relevant activity is subject to the Forensic Science Regulator's Codes of Practice.
Whether the laboratory can demonstrate compliance with those requirements, where applicable.
Whether any limitations or non-compliances will be clearly identified in the expert's report.
It is particularly important to examine the accredited scope rather than relying solely on a statement that the organisation is accredited.
A laboratory may be accredited for one type of forensic examination but not another.
Frequently Asked Questions About Forensic Accreditation
Is ISO/IEC 17025 accreditation mandatory for forensic experts?
Not universally. Accreditation requirements depend on the forensic science activity being undertaken and the applicable regulatory framework. Certain activities covered by the Forensic Science Regulator's Codes of Practice require accreditation, whereas others may not.
Can an unaccredited forensic expert give evidence in court?
Yes. A lack of accreditation does not automatically prevent an expert from giving evidence. The admissibility of expert evidence is determined by the court, taking into account its relevance, reliability and other applicable legal requirements.
What is the difference between ISO/IEC 17025 accreditation and FSR compliance?
ISO/IEC 17025 is an international standard addressing laboratory competence, impartiality and consistent operation. The Forensic Science Regulator's Codes of Practice establish additional statutory requirements for specified forensic science activities in England and Wales. Accreditation to ISO/IEC 17025 alone does not necessarily establish compliance with the Codes.
Does accreditation guarantee that forensic evidence is reliable?
No. Accreditation provides independent assurance that a laboratory meets defined requirements for the activities within its scope. However, individual examinations can still be affected by limitations in the evidence, methodological constraints or errors. The findings must therefore be considered in the context of the examination performed.
Do the FSR Codes apply to defence experts?
Yes. Where a forensic science activity falls within the scope of the statutory Codes, the relevant requirements apply regardless of whether the examination is undertaken on behalf of the prosecution or defence.
How can I check whether a forensic expert is accredited?
Laboratory accreditation can be verified through the United Kingdom Accreditation Service (UKAS). Its publicly available records identify accredited organisations and the specific activities covered by their accreditation. Individual expertise and qualifications should be considered separately.
Conclusion: Understanding the Importance of Forensic Accreditation
Accreditation and regulatory compliance are important considerations when instructing forensic experts or evaluating forensic evidence presented in criminal proceedings.
Although accreditation is not universally mandatory, it provides independent assurance concerning the competence of laboratories and the systems supporting their technical examinations.
The Forensic Science Regulator's Codes of Practice introduce further requirements for specified forensic science activities, helping to establish consistent expectations concerning the quality and reliability of forensic evidence.
For solicitors and barristers, understanding these requirements can assist in making informed decisions about expert instructions and identifying potential issues when reviewing forensic reports.
Verden Forensics provides independent multimedia forensic services to the legal profession, including the examination of audio recordings, video evidence and digital imagery.
Our laboratory holds UKAS accreditation to ISO/IEC 17025 (Accreditation Number 21522) and demonstrates compliance with the Forensic Science Regulator's Codes of Practice for specified forensic science activities.
We are transparent about the accreditation and compliance status of our services, allowing legal teams to understand the quality framework applicable to the examinations they commission.
If you require independent expert examination of audio, video or image evidence, contact Verden Forensics to discuss your requirements.