Polygraph Examinations
This service is offered on a national basis and is carried out by examiners who have undergone extensive professional training at American Polygraph Association accredited polygraph schools. They are experienced certified examiners and continually maintain their training to ensure the most up to date methods and techniques are implemented. The equipment used is the latest computerised polygraph instruments manufactured by The Lafayette Instrument Co.
Our examiners test with a minimum of three charts. This allows for a far more accurate analysis of the results and the examiner can give a very positive result as to whether or not the subject has been truthful.
All of our examiners are AMERICAN POLYGRAPH ASSOCIATION registered. (There is no controlling body in the UK)
We can assist you in the following catagories and may be able to assist in other circumstances not listed below.
- Theft
- Company fraud
- Pre-employment Screening
- Employee misconduct
- Marital Infidelity
- Confirmation of innocence
- Sexual harassment or other allegations
This service is of a very specialised nature and should you need to use this service we will arrange for an examiner to contact you directly. He will discuss your needs and provide advice or information according to the situation. He will also be able to answer any questions or concerns you may have about polygraph examinations.
How the polygraph works
When a person is being truthful there is no stress on the body and it functions without any significant changes. When a person lies the body undergoes certain physiological changes over which they have no control.
The polygraph tracks changes in the subjects physiologoical condition during the examination. This is done by attaching four components to the subject.
Pnuemograph - This consists of two rubber pnuemograph tubes which are placed around the chest and abdomen. These constantly monitor the subjects breathing and any changes to it.
Galvanic Skin Response - This consists of two finger plates placed across the ring and index finger on the right hand. This tracks changes in the subjects skin resistance during the examination.
Cardiosphygmograph - This consists of an item similar to a blood pressure cuff and is placed around the top of the arm. This component monitors and traces changes to the subjects relative blood pressure and pulse rate.
The examiner will do a number of things before beginning the test to ensure correct responses are obtained. These include assessing the subjects emotional state, use of tests to identify the overly responsive and to calm the nervous, ask control questions to evaluate the subjects reponsiveness and carry out a pre-test interview and detailed review of the questions.
Only when the examiner is satisfied with all of the above will he proceed with an examination.
Frequently asked questions
IS THE TEST RELIABLE?
The polygraph in the hands of a skilled examiner is highly accurate. Many studies have been made on the accuracy of polygraph testing and recent research shows the accuracy of the new computerised polygraph as used by our examiners to be close to 100% accurate. However the polygraph is not infalible, if the subject truly believes a lie as he would the truth this will not be detected.
IF A TRUTHFUL SUBJECT IS NERVOUS COULD THIS ADVERSELY EFFECT THE RESULT?
Anyone who takes a polygraph test will be nervous, this is expected, totally normal and does not interfere with the test. Polygraphs register changes in blood pressure, pulse rate, respiration, muscle movement, and perspiration. When a subject is not telling the truth, they trigger an emotional and physical reaction. The trained examiner measures and records this, it is then used to detect a lie. The human body has a set of normal patterns which remain constant, the examiner will have charted these patterns prior to the test.