Hyderabad, July 9: The Central Bureau of Investigation probing the Satyam scam may have successfully secured the nod of court to conduct brain mapping and lie-detection tests on company's former chairman B Ramalinga Raju, his brother B Rama Raju and former chief financial officer Srinivas Vadlamani, but the investigation agency is unlikely to elicit any new information from them.
Even if it secures new information, it will not be admissible in a court of law. This is because brain mapping and lie-detection or polygraph tests are yet to be recognised as tools of evidence by Indian courts. Moreover, experts differ on the scientific aspects and veracity of such forensic tests.
According to Dr S Malini of Forensic Science Laboratory, Bengaluru, these tests will help identify the precise individual, who has perpetrated crime. The tests will differentiate the perpetrator from those who have acquired information from the secondary sources. "Individuals, who have primary encoded information, will show the characteristic brain responses, which are indicative of the possession of first hand knowledge of the event," she said.
The Raju brothers will be subjected to both brain mapping and lie-detection tests. The CBI employed all methods including the carrot and stick policy to gather information from the accused. Since they turned out to be hard nuts to crack, the CBI has banked all hopes on these tests.
Brain mapping test works on the principle that the brain stores information and when subjected to forensic examination will reveal the "guilty knowledge". It is also known as brain fingerprinting test. Sensors are attached to the head of the accused, who is made to sit before a computer. Certain scenes and sounds connected to the incident are played on the computer screen.
The sensors monitor the electrical activity in the brain. They register a special signal called P300 waves, which are generated only if the accused has any link with the photographs or sounds shown or played to him. There will be no investigation of the accused, as in the case of lie-detection test.
In polygraph or lie-detection test, the subject is put to a lot of questioning by the investigating officer. The polygraph test involves recording of physiological responses to the questions posed to the accused. Body responses including change in blood pressure, breathing and body temperature will determine whether the accused is telling the truth.
If the CBI fails to secure the desired information from the Satyam scamsters, it may approach court for narco or truth serum tests, which work on the premise that a person under the influence of intoxication will speak the truth. Though courts in India grant permission for such tests, they do not rely on the reports as concrete evidence. However, such tests have proved handy for investigators to get more details, which otherwise would be difficult to secure.
"The success of the polygraph test depends on the person who prepares the questionnaire. If the questions are pertinent, then correct answers can be generated," said Dr KPC Gandhi, founder-director of Truth Labs.