Deception detection tests (DDTs) such as Polygraph, Narco-Analysis and Brain Mapping have important scientific and legal implications. DDTs are useful to reveal out the hidden information from the accused. This information is sometimes crucial for investigation agencies to assist the investigation process in a number of ways. These DDTs have positive results as well as negative.
The information extracted by these deception detection tests cannot be used as evidence during the trial proceedings in the court. Sometimes investigation gets stuck and at that time investigating agencies needs a further clue to go ahead and solve the case, at this time these tests can be used by investigators. Using these scientific tests in interrogation process will directly help the investigating agencies to gather evidence, and thereby increase the rate of prosecution of the guilty as well as the rate of acquittal of the innocent. Usually, courts don’t prefer to conduct such test on accused because of the infringement of rights of accused under constitutional law.
The difficulties before conduction of these tests on accused are Article 19, 1(a)2 (right to speech), Article 213 (right to life and personal liberty) as well as the right to privacy, Article 20 [3] (prohibits compelled witness against himself)4. These all are constitutional rights of a person which restricts courts to perform such tests on accused. But some modifications in the conduction of these tests and different way of interpretation of some articles of constitution can make these tests reliable and can solve major problems of investigative process and judicial system.