WHAT YOU NEED TO KNOW ABOUT LIE DETECTOR TESTS

  1. Employers are able to use a polygraph for various reasons;
  • Pre employment tests – Prior to employing a candidate an employer can test to see if the candidate has been truthful in their application.
  • Specific incident tests – When a incident takes place, an employer can clear employees that could possibly have been responsible for the incident. A suspect can also be identified.
  • Periodic tests – Random tests can be conducted to confirm integrity of employees.
  1. Employers must make sure;
  • That the employee voluntarily agreed to undergo the polygraph test – Having a signed document is crucial if you ever need to defend your actions in a CCMA hearing.
  • That the employee knows what questions s/he will be asked and understands the questions.
  • That the employee knows s/he is allowed to have an interpreter present – The employee can request to be accompanied by another person, provided that the person doesn’t interfere with the proceedings in any way.
  1. The results of a polygraph test cannot be used as proof of guilt.
  • It is advisable to use the polygraph as supporting evidence and not on its own.
  1. What to look out for when choosing a polygraphist.
  • They need to have completed a course that is accredited by the American Polygraph Association
  • They need to be certified members of a polygraph association
  • Make sure the polygraphist you choose has experience and is willing to testify (a reference track record is advisable).
  • The polygraphists need to have a backup team of forensic investigators to gather evidence where necessary that could follow a polygraph result and confession.
  1. Rates

Rates can average from R600.00 to R 1000.00 (rates would depend on the qualifications and experience of the polygraphist)

  1. Accuracy

Research indicates that the accuracy of a polygraph test is between 90% – 97% accurate, the variation can be put down to various techniques being used.

  1. Lie detector tests in the workplace are not illegal.
  • There is no legislation in South Africa that controls the use of Polygraph Tests in the workplace. There are decided cases where polygraph test results have been accepted as evidence in CCMA and labour courts.