Seraikela-Kharsawan police, on a sticky wicket in the Shanbabu Mukhi murder interrogation, is planning to appeal for lie detector and brain-mapping tests on key accused Santosh Thapa who is dodging queries on twoJamshedpur builders suspected to be the main conspirators in the case.
SP Indrajeet Mahatha said the five-day police remand of Thapa (35) - arrested on Tuesdayin connection with the June 15 killing of the Congress leader on Adityapur Toll Bridge - would end on Saturday and they were making a last-ditch attempt to crack him.
"Thapa is a tough nut. Although he has confessed to orchestrating Shanbabu's murder by hiring killers, he is tight-lipped on the suspected role of the steel city builders whose unscrupulous business practices had earned the victim's protests. Main shooter Chhotu Ram has named the duo. So has the FIR lodged by Shanbabu's widow Ritika Mukhi. But, we need Thapa's corroboration and he won't speak," Mahatha said.
The SP said they were bringing Chhotu to Adityapur thana from Seraikela divisional jail for a face-to-face quiz with Thapa on Friday. "This cross-interrogation is our last resort before we appeal to court for polygraph and brain mapping tests, which need to be done in Gujarat," he said, adding that police had also pleaded for extension of Thapa's remand.
A polygraph machine records the body's involuntary responses to an examiner's questions in order to ascertain deceptive behavior. The test measures physiological data from three or more systems of the human body, generally the respiratory, cardiovascular and sweat gland systems.
Brain mapping is a far more complicated procedure, wherein 32-channel electrodes are placed on the scalp for neurological scan while the suspect is subjected to three sets of questions - the first not related to the case, the second directly related and the third on secret findings in the case.
Shanbabu, the SC/ST cell president of the Congress in Seraikela-Kharsawan was shot dead on the toll bridge during his evening walk. Seven persons, including Thapa, have been netted so far.
