1. Polygraph test

2. Lie Detection Test It is a psycho biological examination .
To check the veracity of the statements of subjects.
With the help of computerized equipment known as lie detector or Polygraph’
Measures 6 different types of autonomic nervous system physiological changes in the form of graph.
Thoracic Respiration by pneumonograph.
Abdominal Respiration by pneumonograph.
Galvanic Skin Resistance by galvanograph.
Blood Pressure by cardiosphygmograph.
Movement or Muscular pressure.
Finger pulse.

3. The above changes are measured by asking sequential questions.
Irrelevant-Is your name x..
Irrelevant-Have you taken your lunch today?
Relevant –Is it a fact that y told to accompany him to visit on 12/3/16?
Control –Before this year ,did you try to kill any body?
Then the changes in above measurements are evaluated to come to a conclusion.

4. The Legal Status of Polygraph Test.
Poly graph examination are not accepted as Evidence it could become an instrument to compel the accused to be a witness against himself violating constitutional immunity from testimonial compulsion.
Article 21 (Invasiveness) &Article20 (3) self incrimination
It is prerogative of individual & test will be illegal & unconstitutional unless it is taken voluntarily

5. Guidelines of NHRC
Test should only on the consent of the accused &option should be given whether he wishes to avail such test.
If agrees access should be given to access to lawyer & physical ,emotional & legal implications should be explained to him by the police &his lawyer.
During hearing before the magistrate the person alleged should be represented by lawyer.
The test be done by an independent agency & conducted in presence of lawyer.
A full medical & factual narration of manner of the information received must be taken on record .
The magistrate shall consider factor relating to the detention including the length of detention.
At the hearing ,the person in question should also be told the statement shall not be a confessional statement to the magistrate but a statement made to a police officer