The polygraph tests began on Saturday for the main accused and six others involved in the alleged rape and murder of a trainee doctor at the state-run RG Kar Medical College and Hospital. Among those being tested is Sanjoy Roy, the primary suspect, who will undergo a polygraph examination in the prison where he is currently held.
The remaining six individuals, including former principal Sandip Ghosh, four doctors who were on duty the night of the incident, and a civil volunteer, will have their tests conducted at the Central Forensic Science Laboratory (CFSL) office in Kolkata. A specialized team from CFSL in Delhi has traveled to Kolkata to oversee the testing process.
What is a Polygraph Test?
A polygraph test, commonly known as a lie detector test, measures an individual’s physiological responses while they answer questions. According to the American Psychological Association, the test attempts to determine if a person has committed a crime, though it does not directly measure honesty. Instead, the assessment is based on the analysis performed by the polygraph operator.
The polygraph machine records physiological indicators such as heart rate, blood pressure, respiratory changes, and perspiration levels during questioning. Sensitive instruments, like cardio cuffs or electrodes, are used to monitor these responses, and a numerical value is assigned to assess whether the individual is being truthful, deceptive, or uncertain.
How Will the Lie-Detector Test Help the CBI?
In the case of Sanjoy Roy, the polygraph test results could help clarify inconsistencies in his statements and alibis. Investigators may be able to identify signs of deceit by analyzing physiological responses that deviate from baseline levels during questioning.
This case, which has drawn significant public attention and protests, has been marked by serious allegations from the Central Bureau of Investigation (CBI). In a statement to the Supreme Court on Thursday, the CBI claimed that local police attempted to cover up the incident, leading to alterations at the crime scene before the federal agency could take over the investigation.
The body of the trainee doctor, who had suffered severe injuries, was discovered in a seminar hall at the hospital on August 9. Following the discovery, Sanjoy Roy was arrested the next day. Amid increasing pressure, the Calcutta High Court ordered the transfer of the investigation from Kolkata Police to the CBI on August 13, prompting the agency to begin its inquiry the following day.