Deception detection tests such as polygraph, brain-mapping and narco analysis are fact finding tools of investigation though the same cannot be used as evidence, say legal and forensic experts. In cases like the Shraddha Walkar murder case where there is no direct evidence, these tools can be used to decode the facts and circumstances that led to the crime. The findings of such tests can then be used to gather scientific and direct evidence, thereby making a watertight case for the trial.

Right to silence not absolute

Advocate Shreeprasad Parab, a constitutional expert, said, “In India, the right to remain silent is a fundamental right guaranteed under Article 20 (3) of the Constitution, which states, ‘No person accused of any offence shall be compelled to be a witness against himself’. And Article 21 states that ‘no person shall be deprived of his life or personal liberty except according to procedure established by law’.”