Central Bureau of Investigation (CBI) officers conducted the lie-detection test on the prime accused in the alleged rape and murder of a lady doctor at the RG Kar Medical College and Hospital in Kolkata.
- The lie-detection test was conducted at Kolkata’s Presidency Jail where Roy is lodged.
- A polygraph test is based on the assumption that physiological responses (heartbeat, changes in breathing, sweating, etc.) triggered when a person is lying are different from what they would be otherwise.
- A numerical value is assigned to each response to conclude whether the person is telling the truth, is deceiving, or is uncertain.
- Neither polygraph tests nor narco tests have been proven scientifically to have a 100% success rate, and remain contentious in the medical field as well.
- In the ‘Selvi & Ors vs State of Karnataka & Anr’ (2010) case, the Supreme Court said tha the results of the tests cannot be considered to be “confessions”. However, any information or material subsequently discovered with the help of such a voluntarily-taken test can be admitted as evidence.
- The Supreme Court Bench ruled that no lie detector tests should be administered “except on the basis of consent of the accused”. Those who volunteer must have access to a lawyer, and have the physical, emotional, and legal implications of the test explained to them by police and the lawyer.
- The ‘Guidelines for the Administration of Polygraph Test on an Accused’ published by the National Human Rights Commission in 2000, must be strictly followed. The subject’s consent should be recorded before a judicial magistrate.
