The Detective Department (DD) of Kolkata Police on Wednesday took over the probe from the Special Investigation Team (SIT) into the alleged rape of a 24-year-old student at a law college in Kolkata.The SIT, initially comprising five members and later expanded to nine, will now assist the Detective Department in their comprehensive inquiry, Kolkata Police said.This comes a day after Kolkata Police Commissioner Manoj Verma noted “swift probe” and said the SIT has gathered “a lot of evidence that is being analysed”.So far, four persons have been arrested in connection with the June 25 incident – prime accused Monojit Mishra (31), a contractual staffer who was a TMC students’ wing functionary; two students – Zaib Ahmed (19) and Pramit Mukherjee (20) – and a security guard, Pinaki Banerjee. It is alleged that the two students allegedly forced the woman into the guard’s room and stopped her from escaping while Mishra raped her.Meanwhile, to strengthen the prosecution’s case, the Kolkata Police has roped in renowned Special Public Prosecutor Bivas Chatterjee, known for his high conviction rate, for the trial.“The handover of the case diary was completed on Wednesday afternoon, marking a new phase in the probe,” said a senior Kolkata Police officer.Meanwhile, the police have added additional charges against the accused. These include BNS sections 77 (voyeurism), 118 (1) (causing grievous hurt), 351(3) (criminal intimidation), 140(3) (kidnapping), 140(4) (kidnapping in order to murder), among others.Story continues below this adInitially, the case was registered under the BNS sections of gangrape and wrongful confinement.“The addition of charges like voyeurism for allegedly recording videos of the assault, and kidnapping, reflects the deepening nature of the investigation and our commitment to building a robust case,” said the officer.In her complaint, the woman has alleged that during the sexual assault, the accused made a video of the act, which they then used to try and silence her. Speaking to The Indian Express, a senior police officer said the woman had told the investigators that the video of the crime was on Monojit Mishra’s cellphone.The SIT had earlier retrieved the CCTV footage of the “eleventh hour” — the hour preceding the crime. Police believe that the CCTV footage will be crucial evidence against the accused.Story continues below this adBoth the Digital Video Recorder (DVR) from the law college’s CCTV cameras and the seized mobile phones of the accused, including that of Mishra, have already been sent for forensic examination.On Tuesday, the Alipore Police court had extended the police custody of Monojit Mishra, Zaib Ahmed, and Pramit Mukherjee to July 8, while the security guard’s police custody was extended till July 4.Seeking 10 more days of custody of the four arrested accused, the police had told the court that medical, circumstantial, and electronic evidence collected by them corroborated the woman’s statement.Meanwhile, the Calcutta High Court is set to hear PILs seeking CBI and court-monitored probes into the rape case. The petitioners sought the transfer of the probe, arguing it was necessary to ensure an impartial probe free from local influence or interference and claimed that the main accused, Monojit Mishra, has a close proximity with the ruling TMC in the state.Story continues below this adThe Division Bench of Justice Soumen Sen and Justice Smita Das De is likely to hear the PILs on Thursday.