look news india
A total of seven people have been subjected to polygraph test in the case of rape and murder of a female trainee doctor at RG Kar Medical College Hospital. The accused are Sanjay Roy, former principal of RG Kar Medical College, Dr. Sandeep Ghosh, four doctors who were with the victim on the night of the incident. Also, polygraph test of volunteers is also being done.
Why does CBI want a polygraph test?
The CBI aims to verify the statements of these personnel, as other medical reports (such as DNA taken from the victim's body, vaginal swab, PM blood) have failed to clearly link them to the incident. The CBI wants to know if the four tampered with evidence or were part of a conspiracy.
The accused is addicted to watching porn
Psychoanalysis of accused Sanjay has also revealed many important things. A CBI official said that the psychoanalysis of the accused indicated that he was a deranged person and was addicted to watching porn. Citing doctors of the New Delhi-based Central Forensic Science Laboratory (CFSL), the official told PTI that accused Sanjay Roy, a Kolkata Police volunteer, has 'animal-like tendencies'.
What is a polygraph test?
Often the police conduct a polygraph test to extract the truth from the accused, in which a lie detector machine tries to detect lies. In which the changes in the body of the accused while answering reveal whether the accused is answering the question correctly or not. In this test, the physical movements of the accused are carefully studied and the answer is decided as right or wrong according to his reaction.
How does this machine work?
It is a machine which has many parts. Some units in it are attached to the body of the accused. For example, machine units are installed on the fingers, head, mouth and when the accused answers, data is received from these units, which goes to the main machine and detects the lie or truth. The units attached to the body include pneumograph, cardiovascular recorder and galvanometer. Apart from this, a pulse cuff is tied on the arm and Lombroso gloves are worn on the fingers. Along with this, blood pressure, pulse rate etc. are also monitored by the machine.
A device worn on the body monitors the pulse rate and breathing through a pneumograph. The truth and lie are judged by the breathing during the answer. It consists of a tube, which is tied around the chest. Heart rate and blood pressure are monitored with a cardiovascular recorder, because abnormal changes occur when lying, which can help detect the truth. Apart from this, the electrical conductivity of the person's skin is checked with a galvanometer. Then this data is collected by a recording device.
