"Three people - Mithun Das, Manojit Biswas and Biswanath Chatterjee - were arrested early Saturday from Madhyamgram area in the district. They were the main accused in the case," said state police’s Criminal Investigation Department’s (CID) Inspector General Anuj Sharma.

Rajib Das was severely beaten up by the three men when he protested their misbehaviour against his elder sister Rinku Das. He died of his injuries later.

"During preliminary investigation we got some clue and later based on the portraits of the assailants sketched by experts based on descriptions given by Rinku, the three were arrested. Three mobile phones were also recovered from them," said Sharma.

The accused have confessed to their crime. Mithun was the main accused who stabbed Rajib. But the knife used in the crime and Rajib’s mobile are yet to be recovered.
However, Chandan Roy, who was arrested by the district police Feb 17 for his alleged involvement in the crime, was freed after it was found he was not involved.
"Even Rinku, after seeing Chandan, confirmed that he was not in the group of youths, who misbehaved with her,” said Sharma.