The CBI on Saturday began its investigation into the Bogtui carnage by visiting the Birbhum village with experts from the Central Forensic Laboratory to piece together what exactly happened on the night of March 21 that led to the death of eight persons.

A CBI team headed by DIG Akhilesh Singh hit the ground running early on Saturday with a visit to the house of Sona Sheikh in Bogtui village from where seven charred bodies were recovered in the morning of March 22.

Over the next two hours, the CBI officers split in multiple groups and scanned the other houses set on fire, as well as examined the entry and exit points, the rooms and terraces.

Armed men had descended on Bogtui within hours of the murder of local Trinamul strongman Bhadu Sheikh on the night of March 21.

A division bench of Calcutta High Court that had Chief Justice Prakash Shrivastava and Justice R. Bharadwaj handed over the probe to the CBI on Friday and directed the central agency to file a progress report by April 7.

Back from the village, some members of the CBI team, including DIG Singh, visited Rampurhat police station under which Bogtui village falls to speak to senior officers of Birbhum, including inspector-general of police B.L. Meena and district police chief Nagendra Nath Tripathi.

The other members got about completing formalities at the Rampurhat ACJM’s court, informing it about the change in the probe agency from the special investigation team to the CBI on the orders of the high court.

At the police station, the CBI officers spoke to the Bengal cops, including Swargajit Bose, who had been the investigating officer in the case.

“The officers from the CBI asked several questions like the time of the first call from the village, the fire on the night of March 21 and the locations where the charred bodies were found.... The preliminary findings of the probe by the special investigating team were also discussed,” said an officer.

At Bogtui village, forensic experts measured the distance of different locations from the road from where the armed attackers came on Monday night.

The team had brought with them 3D sensors, compasses and measuring tapes.

They collected evidence such as iron rods and a few charred items, among others, from the fire-ravaged homes of Sona Sheikh and three others.

“The items that were collected will be examined in our laboratory in detail,” said a forensic official who also explained how the 3D scanner helps them ascertain even minute impressions.

“The agency is preparing a map and is gathering details of crime scenes one after another. This will help during a detailed investigation,” said a source.