A modern Polygraph Machine
A Polygraph Instrument is, in effect, a sophisticated piece of medical equipment which measures autonomic nervous reactions which take place in the human body when an 'important', or incriminating, lie is told. These responses are usually not visible to the eye. The physiological reactions which occur when a person tells a lie are measured by recording respiration, cardio-vascular reaction and skin moisture changes.
Since the beginning of the twentieth century, the Polygraph has been widely used, particularly in the USA, by Governments and Law Enforcement Agencies - always with the full consent of the subject. Experts claim an accuracy of up to 99% in their findings and no other systems used for lie detection purposes have come close to the range of accuracy achieved by the Polygraph.
Our work involving the Polygraph falls into three main categories:
- Pre-employment screening. To verify that information given to employers by potential employees is truthful.
- Honesty maintenance. A programme to help employers to contain and eliminate staff theft.
- Specific investigations. To identify the perpetrators of particular incidents, such as theft (of cash, property or information) and marital infidelity.
Nationwide Investigations Group emphasise that the Polygraph is often used to confirm innocence rather than to establish guilt. If a loss has occurred, pressure is inevitably imposed on innocent parties and the Polygraph can help to dispel the unpleasant aura of suspicion which can surround such an incident.
When we updated our equipment to state of the art computerised versions, Madame Tussaud's were keen to acquire one of our older models, which can be seen at the FBI section displaying a Tony Blair waxwork being tested.