(Image source from: Livemint.com)

The CBI on Wednesday initiated proceedings to conduct a lie detector test on ASI Anup Dutta of Kolkata Police to ascertain his alleged connection with Sanjay Roy, who was arrested in the murder of a resident doctor at RG Kalka Medical College Hospital, the official said. The Central Bureau of Investigation (CBI) got permission from a Calcutta court to conduct a polygraph test on sub-inspector Dutta, who had earlier been questioned by the agency in the case. Dutta will be the eighth person to undergo a lie detector test in this case. Dutta, a member of the Kolkata Police Welfare Committee, had done a favor for Roy, a volunteer traffic police officer, officials said. CBI is investigating whether Roy informed Dutta about the alleged crime and whether he took precautions to cover up the crime, sources said. Information disclosed during a polygraph test will not be used as evidence at trial, but the agency may collect supporting evidence that can be used in court.

Lie detector tests can help assess the inaccuracy of statements from suspects and witnesses. By monitoring the subjects' psychological responses, heart rate, breathing patterns, sweat and blood pressure, researchers were able to determine whether there were differences in their responses. The trainee doctor was raped and murdered in the seminar room of the RG Kar Medical College and Hospital in the early hours of August 9 while he was resting during her graveyard shift. Her body with signs of serious injuries was found by the police in the hall. Roy was arrested the next day based on CCTV footage that showed him entering the seminar room at 4:03 a.m. on the day of the incident. He was questioned at length due to a “recent injury” to his left cheek and a scratch to his left hand. Police noted signs of a struggle, particularly on the back of her left thigh. Biological samples such as urethral swabs and swabs, semen, hair and nail clippings, and nail files were collected during medical and legal examinations. On August 13, the Calcutta High Court ordered the transfer of the investigation from the Calcutta Police to the CBI, which took over the case on August 14. After taking over the case, the CBI booked former medical college principal Sandeep Ghosh Roy, four doctors who were on duty with the victim, and a volunteer citizen who conducted lie detector tests to obtain further clues about the crime.