The CBI, probing the rape-murder of a woman doctor at RG Kar Medical College and Hospital here, is concentrating on how the crime was executed without any hindrance in the facility’s seminar hall where the door’s tower bolt was found broken, an officer said.

CBI officials are also trying to find out if someone was stationed outside the seminar hall to ensure that the crime went undisturbed, he said, adding that the investigators are analysing CCTV footage to confirm it.

The investigating officers wondered why nobody could hear any sound from inside the seminar hall when the victim was being tortured.

"The tower bolt was broken, which caused the door to malfunction. We are probing whether anyone was stationed outside to act as a guard while the crime was committed," a CBI officer told PTI.

Initial findings indicate that the door, due to the broken tower bolt, had been malfunctioning for some time. The victim entered the hall between 2 AM and 3 AM on August 9. A doctor on duty reported seeing her asleep inside the hall, the officer said.

"Interviews with doctors, interns, and junior doctors revealed that the door’s malfunction had been a known issue, which prevented the victim from locking the door that night," he added.

On Friday, the agency continued questioning Sandip Ghosh, the former principal of RG Kar Medical College and Hospital, in connection with the case. Additionally, the CBI presented the arrested suspect, Sanjay Roy, in court, which sent him to 14-day jail custody.

The body of the postgraduate trainee doctor was discovered inside the seminar hall on August 9. A civic volunteer was arrested the following day in connection with the crime.

The CBI took over the probe from Kolkata Police following a Calcutta High Court order on August 13.

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