Investigative services

Credibility Assessment

The Centre for Forensic Neuroscience, established in 2002, provides polygraph testing services (often referred to as lie detection) and credibility assessment with the UK’s largest team of dedicated expert examiners, with Dr Keith Ashcroft as the Principal Forensic Polygraph Examiner. Each are established professionals in their own discipline, and are available for instruction in your location throughout the United Kingdom, Europe, the Middle East and the rest of the world.

We are members in good standing at the National Polygraph Association (USA), The British Polygraph Association, the American Association of Police Polygraphists, as well as the American Polygraph Association. We have been trained at American Polygraph accredited & British Accreditation Council academies, including advanced training at the Behavioural Measures UK Polygraph Training Centre operated by Behavioral Measures, and also members of the Society of Forensic Interviewers; we are therefore conversant with best practice.  As such we are independent, impartial and objective in our professional work.

We specialise in providing specific issue examinations using only accepted protocols and standards in accordance with the American Polygraph Association and ASTM International (committee E52 on Forensic Psychophysiology). We employ strict quality control procedures, as well as using two examiners to confirm results. Our state-of-the art computerised polygraph systems, such as the Limestone Paragon Acquisition System, have a High Resolution 24 bit Analog to Digital Conversion for superior recording and analysis capability.


For resolving relationship difficulties, including financial investigations between intimate partners.


Victim and alleged perpetrator testing in those having legal representation only. In cases where polygraph examinations are not feasible we can employ a Visual Assessment of Sexual Preference.


In legal terms, a child is defined as anyone under the age of 18. Therefore, safeguarding children is about protecting all those under 18 from harm. This can be done by investigating individuals with access to children, either in an employment context, or within an intimate or family relationship. 


Polygraph testing for private sector employees who are under investigation for allegations relating to economic loss to their employers.


Prevention, detection and investigations of insider attacks.


Polygraph used within a therapeutic setting to assist in disclosure, sobriety and relapses in sex addiction; as well as treatment resistance etc.. We work with the Laurel Centre, Leamington Spa which offer proven psycho-educational programmes for the treatment of sex and pornography addiction and support programmes for partners.


We provide polygraph screening testing for Public and Private sector companies, as well as periodic honesty testing, including drug screening. Our services include psychometric testing using the Holden Applicant Screening Measure. The Holden Applicant Reliability Measure was developed by Dr. Ronald Holden at Queen’s University and has been further researched by Dr. Angela Book at Brock University. This dynamic psychometric instrument provides valuable insights on employment candidates in an effort to save resources related to recruitment and training.

PAIRED TESTING (Marin Protocol)

Used in situations where one of two opposing witnesses is most likely being deceptive. Effectively used in mediation contexts.


For identifying concealed assets.


Polygraph testing for those who have been granted leave to Appeal (N.B. ~ in the UK this cannot form the basis of appeal against conviction) (Pro Bono).


Polygraph testing for those alleging acts of misconduct or accused of same.


Polygraph testing of individuals seeking asylum are used to determine the validity of the claims of the petitioner in immigration cases. The statements of the petitioner requesting asylum can be verified by a polygraph test. The results of the test can assist in making an informed decision with regard to granting or withholding asylum.


Forensic / Criminal matters: such as homicide, sexual violence, theft, fraud, sabotage, and espionage. Allegations of sexual abuse are subject to our enhanced service with two forensic polygraph examiners. CFN provides solicitors and lawyers with an assessment as to the credibility of the defendant and witness in criminal matters.


To effectively manage sex offenders in the community.


Polygraph testing to assess the value of critical intelligence sources.




How to Schedule a Polygraph Interview & Examination:

  • You can schedule a polygraph interview and examination by using our contact form, or by calling us directly on 07790732828 to speak directly with an examiner, so we can provide an in-depth description of the process, fees, advice, and guidance for the examinee in readiness for polygraph testing.
  • When requested, we can have a polygraph examiner conduct the interview and polygraph examination at a office in your location to satisfy the required optimal testing environment; therefore our fees reflect this best practice level of service.
  • In accordance with the American Polygraph Association recommendations, and good practice, we do not conduct tests in a home environment.
  • Please note our fees are dependent upon the gravity of the issue to be investigated and the distance from our test centres.
  • A retainer fee is normally required to secure the appointment. We use WorldPay for all financial transactions and billing.
MUST HAPPEN ON voluntary basis
It is vitally important to stress that all examinations must be taken on a voluntary basis. No person should be intimidated or coerced into taking such an examination. If you have been threatened to participate in a polygraph interview and examination, then this could have a negative influence over the whole testing process. As a strict policy we do not accept instructions where we believe coercion or threats are present.
Fees vary on the type of exam and where it will be conducted. Credibility assessment requires extensive training, continuing professional development, as well as specialised instrumentation, therefore our fees reflect this fact. Our examiners are also qualified as Expert Witnesses.
neutral testing environment
Usually we can arrange a suitable neutral testing environment in your particular location to ensure that tests can be conducted in a proper manner. For therapeutic services, our consultants use clinic settings, should this be a necessary requirement.
it takes 2 hours or more
Please also note that the whole process takes around two hours or more to complete.
single issues question formats
You will be advised that we strongly recommend only single issues question formats as this has been proved scientifically to be the most accurate method to employ. Thus for example:

R1   Did you take the money from the First bank in Mosley Street, Manchester last Thursday?

R2   Did you take the money from the First bank located in Mosley Street, Manchester last Thursday?

R3   Did you take the money that First bank in Mosley Street, Manchester on Thursday last week?

Furthermore, the answer to each question is limited to either ‘yes’ or ‘no’. Compound questions or questions that ask for opinions, feelings, emotions, intent, or, frame of mind are not appropriate and cannot be used. Hypothetical questions or questions about future behaviours must not be used.

Any additional issue must be done with a separate polygraph test. Examinees will be sent information on how to prepare for the test and be evaluated for suitability according to various criteria; such as for example:

  • Be free of any serious illness.
  • The examinee should not have been subjected to any accusatory interviews prior to the examination.
  • The examinee must not be under the influence of alcohol or substances of abuse at the time of the test.
  • The examinee must have had a reasonable amount of sleep prior to the test.
  • The examinee must have prepared and be notified at least 48 hours prior to the actual test.
It should be noted that there are certain limitations of polygraph testing:

      • The test results relate to what the examinee perceives.
      • Not everyone is suitable for testing due to individual physiological and psychological differences and states.
      • The clarity of issues being tested.
      • Number of issues being tested.
Our examiners work in conjunction with specially trained interpreters to provide polygraph tests in most languages. They are also trained in cross-cultural sensitivities in order to engage more effectively with people from different cultures.
Please note the our examiners do not re-test the work of other examiners as a matter of company policy and professional ethics.
In most cases the results are given during the examination process, or, soon thereafter if a peer review is necessary.
The examinee must provide government identification (Photo ID Card, Passport, Driving License ) on arrival for verification purposes.


The underlying theory of how the polygraph instrument identifies the particular arousal pattern for each channel does not rely on fight, freeze or flight i.e. threat of punishment, consequences of being caught lying or even psychological set. Nor is it a conditioned response, or related to anxiety (there is no basis in research for this). These notions are outdated and irrelevant to modern polygraph science. Current understanding refers to what is known as the ‘orienting response’ to novel or important stimuli, which are intrinsically related to experiences in autobiographical memory, emotional salience and the act of lying requiring increased cognitive processing. Specifically, it takes more cognitive activity to lie than to tell the truth because you need to construct a narrative, so the degree of cognitive processing can be relevant in determining deception. This collection of underlying neural processes give rise to increased autonomic arousal that is routinely detected by the polygraph instrument. Thus, essentially, we are analyzing the strength of attention as determined by autonomic arousal.