The CBI has decided to conduct forensic psychological assessment of the nine persons arrested in connection with the killings in Birbhum district of West Bengal, an officer said on Saturday.
During the assessments, one psychologist will be present to note their body language as well as facial expressions, which will be treated as evidence, he said.
"Forensic psychological assessment will be used while grilling the nine suspects. This is to ascertain whether these persons are telling the truth or lying," the officer told PTI.
"A psychologist will be present and he will file his findings as a report, while will be produced as evidence in the court," the officer added.
The decision was taken after CBI found inconsistencies in their statements about the incident, another official said.
The probe agency has interrogated the officer-in-charge of the firefighters who were involved in the rescue operations at the 10 houses in Bogtui village which were set ablaze after the killing of local TMC leader Bhadu Sheikh, the officer said.
The CBI has also decided to send samples of the eight people killed in the carnage for DNA tests.
"The affected families have told us that they were unable to identify the bodies. The DNA tests will help us in identifying them," the officer said.
Charred bodies of the eight people were recovered from Bogtui village in Rampurhat police station area of the district, hours after the murder of the TMC leader.
The incident, which happened on March 21, sent shockwaves across the nation with the Calcutta High Court directing the CBI to take over the probe.
