Narcoanalysis, Polygraphy and Brain-Fingerprinting, generally known as lie detector tests, have recently been under scanner and debate among professionals, scientists, legalmen and the civil society as to the genuineness and reliability of these tests. One faction claim these tests to be fool-proof, while the other consider them as pseudo-science, besides being hazardous to health. The book discusses in detail the arguments and scientific facts put forward by both the sides and the underlying truth. Part `A` of the book deals with the scientific nature, used methodologies to conduct these tests and their drawbacks, while Part `B` contains legal aspects of the tests, supported by courts decisions, both, Indian and foreign. Relevant parts of Forensic Psychology and conventional methods of interrogation for lie detection have also been included. The book has been designed to help professionals, securitymen, prosecutors, members of civil society and of course the collective legal fraternity.