Polygraph Testing is used to determine if suspects or witnesses are conveying the truth in relation to the investigation at hand. Polygraph examination consists of three main steps:
Pre-Test Stage: The examinee is advised of their rights, the details of the investigation that is being conducted, and that the polygraph test is voluntary. The examinee will be required to complete a consent form. The examiner is also required to complete certain documents. The instruments to be used in the testing process and their functions are explained to the examinee. The examinee is given the opportunity to ask questions, which must be answered by the examiner. The examinee will be asked to describe any events that he / she may be aware of that relates to the investigation, from his / her point of view. The examiner will formulate the questions to be asked in the polygraph test and discuss these questions with the examinee. The instruments will be attached to the examinee, ensuring at every step that they are comfortable.
In-Test Stage: The examiner will conduct a minimum of three (3) separate tests, each lasting about five (5) minutes. The maximum number of tests that may be conducted is six (6). (The test consists of the questions formulated during the pre-test phase and the examinee has a two (2) minute relaxation period between each test).The examinee’s physiological data is collected on the polygraph charts while he / she answers the questions put forward.The results of the test are analysed, and the examiner will express his opinion using the following professional options:
- No Deception indicated
- Deception indicated
- Inconclusive
Post-test Stage: If any deception is indicated by the examinee in relation to any of the questions asked during the in-test stage, the examinee is given the opportunity to explain these reactions. The examiner will provide the client with a written report based on the results of the polygraph test.