I’ve recently read much about the lie detection scenario including the latest Labour Court case on this. It must be borne in mind that lie detection and in particular polygraph testing is just a tool. It cannot constitute conclusive evidence and nor can it be used as the sole testament to proof of guilt. The real value in polygraph testing is often the discussion before and after the test.
My experience has shown me that these discussions with a skilled polygraph practitioner are incredibly valuable because employees often tell the truth about others or confess. It is important for that tester to have someone with him or her so that these confessions and the offers of providing evidence against others are properly recorded and used in due course.
More often than not, the tension surrounding a polygraph test elicits frank discussion and sometimes even enormous defiance. It’s useful to add this into the mix in theft and fraud investigations.
With the enormous growth of white collar crime and the statistics we are seeing on shrinkage in the retail environment, employers are faced with the breakdown of the trust relationship in many instances. This trust relationship is often difficult to prove at a disciplinary hearing. An employer only needs to show that this trust relationship has been broken on a balance of probabilities and often a single witness is sufficient.