Kolkata: The Central Bureau of Investigation (CBI) is set to take a major step in the Kolkata doctor rape and murder case. It is learnt that a polygraph test may be conducted on the former principal of RG Kar Medical College and Hospital, Sandip Ghosh to find out more details and the agency is now waiting for the court's nod.
According to sources, the CBI has initiated the legal steps before conducting the polygraph test of Ghosh. The sleuths have approached the court after getting a green signal from CBI headquarters in Delhi.
What is a polygraph test?
Sources said that the polygraph test is done to confirm whether a suspect is saying the truth or not. Investigators basically want to know whether the person is cooperating with the investigators or he is lying. Also, it is revealed whether the accused is concealing something or not.
The test becomes imminent to assess an accused's mental state like palpitation or tension when he is giving any information to the detectives of the investigating agency. Several aspects are taken into consideration including his breath count, whether he is stressed, whether his blood pressure is stable and how much his body is sweating while answering queries.
During the polygraph test, a detailed information about the accused's body is available. According to CBI sources, the polygraph machine usually records four things namely breathing rate, pulse rate, blood pressure and how much sweat is produced.
"When a person tells a lie, a special signal called P300 is released from the brain. That is an important signal for us because of that neural signal, his heart rate and blood pressure increase. The whole matter then becomes clearer to us. It is easier to make a decision," a CBI officer told ETV Bharat.
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