Understanding Validation

The Supporting Validation Guidance document is now available to download. The document highlights the key points discussed in the video as well as provides additional visuals to help support understanding of validation and the method development cycle.

The above specially produced video explains the difference between validation and method development.

It features the Forensic Science Regulator Gary Pugh OBE explaining the importance of validation for giving confidence in forensic science entering the criminal justice system.

What is Validation?

Validation is a comprehensive scientific study which includes a series of tests that produces objective evidence that a finalised method, process, or equipment is fit for the specific purpose intended.

    The Forensic Capability Network are supporting the forensic community to improve quality standards and achieve and maintain accreditation more efficiently through collaboration. We are harnessing the strengths and successes across the forensic community to benefit all, and we are enabling knowledge sharing across the forensic community. Forces can draw on lessons learnt and utilise shared materials to reduce risk and accelerate compliance to the FSR requirements, aligning to the ‘once for the benefit of many’ ethos.

    What does the validation process entail?

    • Determining and reviewing the end user requirements and specification, 

    • Risk assessment of the method,

    • Setting and assessing the acceptance criteria,

    • Producing a validation plan,

    • Completing the validation exercise,

    • Producing a validation report

    • Producing a statement of completion

    • Providing an implementation plan.

    Why is validation important?


    Forces must declare their compliance to the FSR Code which requires confirmation that validation has been undertaken for the FSAs conducted.

    Validation studies test method limits, identify potential for error, and ensure methods are fit for purpose and that any limitations are well understood and communicated appropriately. 

    Validated methods and processes mitigate risk of miscarriage of justices. 

    Validation in Policing - Current Challenges

    Validation is often seen as a check box compliance exercise, immensely time consuming and resource intensive with differing approaches to testing of methods resulting in no national consistent approach.

    This means Policing have missed opportunities to share knowledge, build a cohesive response to quality challenges and embed a valued quality culture which risks undermining trust in forensic processes across the CJS.

    Horizon scanning and future risks and threats

    Validation supports innovation and can be used to introduce new methods, tools and techniques into Policing. It is important to ensure any new methods and technology are tested robustly first to ensure they are fit for purpose.

    Horizon scanning and assessing future risks and threats can support planning of future national validation.

    The FCN work closely with a wide variety of stakeholders and partners to support future enduring capabilities. Further information can be found on our website. 

    Our response

    The FCN are supporting forces with validation support by reviewing validation documents and sharing findings with the aim of a centralised validation library. We are providing national advocacy on behalf of forces liaising with UKAS and the FSR Unit to support compliance to the Code, reduce risk and improve understanding. We are collaborating with key partners to build enduring capabilities which support GTD requirements and are working to improve proficiency testing provision. Finally, we will support the forensic community to horizon scan for new techniques and methods, improved understanding of risks and trends and enabling a more efficient and effective accreditation process.  

    Forensic Capability Network - Validation Support activity

    • A bi annual review of the Validation Support strategy and associated delivery plans to ensure the forensic community is optimising opportunities and positively impacting on forensic services.
    • The Validation Support function will review current challenges and priorities identified forensic community via feedback and workstreams.
    • Keep a validation risk matrix to identify and track present and future validation risks affecting the forensic community.
    • Community driven validation road maps discipline specific.  
    • Facilitate enable coordinate and support validation activity across all forensic science activity.
    • Seek efficiencies where possible for validation activity.
    • Support knowledge sharing with the forensic community.
    • Support Horizon scanning for new techniques and methods for FSA’s.

    Validation Documents

    The FCN have produced a suite of Validation documents which are stored in the Library of the FCN Knowledge Hub Group. We welcome new members from within Policing to join the Group.

    We can also share community validation through the group if you would like to share it.

    The NCA Fingerprint Bureau have been accredited to process Digital FRD (friction ridge detail). The NCA have kindly shared their suite of validation documents for this and they are available in the Library.

    Method Development and Validation Cycles

    Method Development and Validation Wheels

       Download Method Development Wheel                                                               Download Validation Process Wheel

    Thanks so much – will work my way through the corrections. There were definitely a few areas I overlooked! Really helpful to have your review and today’s discussion.

    DNA Laboratory Manager – Anon Force

    Thank you for your thorough review of this plan, really useful.

    FEL practitioner – Anon Force

    Thank you so much for your time. You have potentially saved us 1000's of pounds.

    CSI Technical manager – Anon Force

    Why do we undertake validation?

    • Validation is based on robust scientific tests which provide practitioners and the wider CJS with confidence and reassurance in the forensic methods, processes and equipment being deployed in laboratories and at scenes.
    • Validation is the mechanism in which forensic units ensure methods are fit for the purpose intended and support the production of evidential material for Court that is adequate, relevant, and reliable.

    What is verification?

    Verification is confirmation through further scientific testing, that a finalised method, process, or equipment, remains fit for the specific purpose intended. In a forensic unit where validation of a finalised method has been undertaken more than once, verification can be conducted with a smaller set of tests to verify that everything still works as it should. Adopting forensic units can undertake verification to demonstrate the process works in their hands as long as the method, process or equipment is deployed in the same way.

    When should we undertake validation?

    • Validation is a continuous iterative process and should be undertaken for all methods a forensic unit intends on using, including those infrequently used.

    Who benefits from validation?

    • The Criminal Justice System benefits from validation as Courts can be reassured that evidence has been produced reliably tested via scientific methods.
    • Forensic practitioners benefit as they can deploy these methods knowing they have been robustly tested and signed off by their forensic unit reducing the risk of missing evidence and producing erroneous results.
    • Investigators can confidently pursue further lines of enquiries knowing that forensic reports have been produced using validated methods.
    • The public can be reassured that forensic evidence is presented to the courts without bias and based on scientific testing.

    How can validation be explained in layman’s term to non technical colleagues?

    Validation is an activity that supports confirming that a process has been tested, documented and works for the customer. Processes/tools/methods can be tested by manufacturers but their scope might be wide and not focused on accuracy. Validation focuses on end users and their requirements, providing definitive proof that the process/tool/method works for the customer (for example the investigator) and the output is reliable and accurate when taken to court. 

    Who should undertake validation in forensic units?

    • Validation should be conducted by trained and competent practitioners in the relevant forensic discipline. Evidence of training and competency should be documented in the appropriate training records.
    • Practitioners with different levels of experience should be included in validation; therefore, representative of users of the method.
    • Practitioners from the location / base or unit where the method will be used should be included in the exercise.

    What types of validation are there?

    There are different types of validation, including method validation, instrumental validation and software validation. Each type of validation has its own specific requirements. For forensic units, method validation needs to be conducted in line with the Forensic Science Regulators Code.

    Does validation only need to be done once?

    • The frequency of validation within forensic science depends on a number of factors, including the type of method or process being validated and the intended use of the results.
    • Validation should be conducted for each new method or process, and then reviewed periodically thereafter and consideration given to whether any further validation or re-validation is required. For example: a new DNA analysis method might be validated once before it is put in use. The validation would then be reviewed, and this may identify that the validation could be expanded, or that re-validation is required. Timescales for validation review will depend on the stability of the method.
    • In addition to periodic validation review, forensic methods and processes should be validated whenever there are changes to the method or procedure, such as when new equipment is used or when the method is applied to a new evidence type.

    What is a method?

    A logical sequence of operations, described generically for analysis (e.g. for the identification and/or quantification of drugs or explosives, or the determination of a DNA profile) or for comparison of items to establish their origin or authenticity (e.g. fingerprint/footwear mark/toolmark examination; microscopic identifications).

    What is a process?

    A series of actions or steps taken in order to achieve a particular end.

    Contact us

    Whatever support you'd like with validation, please get in touch with our team. We also welcome suggestions for new areas of validation and details of any new validation undertaken by the community.