Police on Wednesday arrested commandant of the Tripura State Rifles (TSR) Tapan Debbarma, in connection with the killing of senior journalist Sudip Datta Bhowmik at the 2nd battalion headquarters near here on Tuesday. His personal bodyguard Nandalal was earlier arrested for shooting down the journalist allegedly on the instructions of the commandant.Both the accused booked under IPC Sections 302, 109 and 27 of the Arms Act were sent to police remand for a period of 10 days when they were produced before the west Tripura Chief Judicial Magistrate. They have been kept at a city police station for interrogation by the CID, which has been entrusted with the investigation.Initial interrogation of accused rifleman Nandalal revealed that the killing of Mr. Bhowmik occurred inside the office chamber of Mr. Tapan. “He told us that despite his reluctance the commandant forced him to open fire,” a police officer told The Hindu on condition of anonymity.“After firing a single shot from his AK 47 automatic weapon, Nandalal became nervous and hurriedly left the room leaving the journalist in a pool of blood. The commandant let the critically wounded journalist die without medical attention.”The senior crime reporter had written 11 articles in daily Syandan Patrika against massive financial irregularities in the 2nd battalion of TSR.