KOLKATA: Bengal higher education department directed Monday a south Kolkata law college to expel Trinamool Congress Chhatra Parishad functionary Monojit Mishra alias Mango and rusticate Zaib Ahmed and Pramit Mukherjee, accused of gang-raping a 24-year-old student inside the campus guard room on June 25.Officials ordered the college to issue a show-cause notice to its security agency over lapses and restrict outsider entry. Police said its SIT was examining 17 students present that evening, including eight who lingered longer on campus.“Altogether, 17 students were present. Eight remained longer, including the survivor and the accused. The statements of the remaining four will be crucial. Two have been examined,” a police source said. SIT is also analysing CCTV footage, including images from gate 1 that provide “conclusive evidence” tying the three accused to the crime. Investigators established that Ahmed bought an inhaler for the woman at 8.29pm, supported by a shop bill and CCTV footage, indicating the assault occurred between 8.30 and 10.50pm.Police arrested security guard Pinaki Banerjee, 55, for “facilitating the crime” after inconsistencies in his answers. Police plan to record his statement before a magistrate, calling him a primary witness to 31-year-old Monojit’s alleged “fiefdom” in the guard room and union room.Security guard Banerjee claimed he was threatened not to report the crime and “forced and confined” inside the union room. “But why did he help lock the main gate, preventing the woman from leaving? Why didn’t he inform authorities or police later?” said an investigating officer.