Lie Detector Test- A Know How

Updated: October 18, 2017

Since times immemorial people have resorted to many ways to get truth out of individuals. There were various ways and they not only worked on the psyche of the individual but his/her weaknesses. There are instances in history wherein the person would be tortured relentlessly using brutal methods till they submitted the truth. But now in more civilised society where law takes it course and science has evolved to such an extent that it has easier to detect if the person is lying under oath. There are truth serums too, which help the individual blurt out the mystery that wouldn’t surface so easily. Lie detector test help in investigations

The truth may be unpleasant and hard to digest but it has to come out and it will bring justice in place. At times the gory details of truth can make many seeking it back out. But there are certain professionals trained for this purpose, and they work upon the person to get the bare truth out and this way it can help many who are fighting to get justice or are victimised.

The person is totally wired to the machine and the professional will ask a series of well prepared questions that have to be answered by the person.


The examiner will have prior information about the person undergoing the test without undermining the person or situation, the examiner has to form a set of questions that will bring out the truth. The questions asked will alternate from relevant to irrelevant so that the person who is being tested does not get used to a pattern and become comfortable and assume what would be next question and be prepared with the answer. This way the examiner ensures that the person is caught unawares and brings out the truth without thinking about it. This controlled questioning technique is criticised for they way the questions are put forth and it may sometimes elicit a wrong response from a nervous innocent person too.

There are other kinds of tests conducted all over the world who do not find the above technique that much useful for their validation to hold someone as guilty. It is also known as the guilty knowledge test or the concealed information test, here the examiner is not given prior information of the person being tested and the questions will be new to both the persons. There will be multiple choice answers which the person has to choose from and he may have to answer in a definite yes or no or give precise answers as to how many persons were there or the number of times the pistol was fired etc.

The validity to these tests rests on the fact that the back information and evidence gathered will be supplemented in coming to a conclusion. The sole lie detection process will not prove that a person has to be guilt, it is just one of the methods of getting out clues and information to help gather evidence and bring about clarity in the case.