NEW DELHI: Three of the four people arrested for the alleged gangrape of a female student at a law college in Kolkata had planned the act in advance, a police officer said on Monday.“The entire matter was premeditated. The trio had been plotting for several days to carry out this torture on the victim. We have found that the victim was targeted by the prime accused from the very first day she got admission to the college,” the officer was quoted as saying by the news agency PTI.The Special Investigation Team (SIT), made up of nine members, is probing the case. The SIT found that the three accused Monojit Mishra, Pratim Mukherjee and Zaid Ahmed had earlier been involved in sexually harassing other female students of the same college, as per the PTI report.The fourth accused in the case is the college’s security guard.According to the police officer, as cited by the PTI, the three accused used to record such incidents on their mobile phones and later blackmailed the victims using the footage.Kolkata Police is now searching for mobile videos that were possibly recorded by the accused.“Searches were conducted at the residences of accused Mukherjee and Ahmed on Sunday. We are looking for footage related to this and possibly other incidents,” the officer was quoted as saying by PTI.Investigators also believe a video clip of the June 25 incident may have been shared.“We are trying to find out whether those clips were forwarded or shared with some other groups. In that case, we have to get in touch with those who have received that,” the officer further said, as cited by the PTI.The SIT has made a list of more than 25 people, mostly students of South Calcutta Law College, who were present at the college on the evening of June 25.“All these people will be questioned in connection with the investigation. We have to find out what they witnessed that evening,” the officer said.The incident involves a female student of South Calcutta Law College in the Kasba area of Kolkata. She was allegedly gangraped by three persons, including a former student and two current students of the college.