MINIMUM REQUIREMENTS FOR A VALID POLYGRAPH EXAMINATION:
There are certain prerequisites that should be kept in mind when determining whether a polygraph examination is valid. This is of particular importance when considering the use of polygraph results as evidence. The following are minimum requirements for the acceptability of a polygraph in a disciplinary hearing, the CCMA or in court:
- The polygraphist must have been trained at a polygraph training facility accredited by the Southern African Polygraph Federation. This implies adherence to a strict code of conduct and ethics.
- The polygraphist must be a member in good standing at the Polygraph Association of South Africa.
- The polygraphist must be experienced enough to be able to analyse the chart tracings or polygrams and such experience must have been gathered while working under supervision.
- The polygraphist must be independent, impartial and objective.
- The polygraph technique and test procedure must be explained to the examinee.
- Polygrams or chart tracings must be assessed manually and computerised evaluation may be used only for the purpose of quality control or to obtain other opinions.
- The polygraphist must be able and willing to testify as an expert witness.
- The examination must be done voluntarily and this must be stated in writing.
- The examinee must be, as far as can be ascertained, free of serious illness.
- The examinee should preferably, not have been subjected to accusatory interrogation prior to the examination.
- The examinee must not be under the influence of alcohol or narcotics at the time of the examination.
- The examinee must have had a reasonable amount of rest prior to the examination.
- The examinee must have been prepared and notified in advance about the examination.
The Polygraph Instrument
- The instrument must be properly calibrated according to manufacturer’s specifications.
- The instrument must be in good working order and record at least three channels.
- At a minimum, the device should record tracings for cardiovascular and breathing patterns as well as galvanic skin responses.
The Polygraph Technique
- An internationally accepted, valid questioning technique must be used.
- All questions must be thoroughly reviewed with the examinee before the collection of charts takes place.
- A minimum of three polygraph charts should be recorded during the chart collection phase of the examination.
- The environment in which the examination is administered should be conducive to proper polygraph testing, i.e. a quiet environment without serious visual or audio interference.