The 17-year-old girl who was allegedly gangraped at a park in Southeast Delhi last month has identified all three accused during a Test Identification Parade (TIP) at Tihar Jail on Wednesday, official sources said.The three accused — Asif, Hemant Singh and his brother Mukesh — are lodged at the jail.A TIP is a procedure in criminal investigations in which a victim or witness is asked to identify an accused before a magistrate. The process is conducted in the presence of the investigating officer to ensure there is no mistaken identity, which could lead to a wrongful conviction.Police said they are trying to build a watertight case. Weapons like the firearm and knife used in the crime have been recovered; forensic report of the evidence is awaited.Posed as cops, assaulted girl on 17th birthdayThe incident took place September 21 when the girl and her male friend were walking through Aastha Kunj Park after offering prayers at a nearby temple on her birthday.According to police, the accused allegedly posed as police officers and threatened the teenagers with a gun and a knife.The accused allegedly demanded phone numbers of their families. When the teenagers refused, the men allegedly slapped the boy and forcibly separated him from the girl.Story continues below this adPolice said the three men then raped the girl one after another while one of them restrained her friend.The boy made a PCR call at 8.45 pm, informing the police that he and the girl had been assaulted by three policemen inside the park. A police team reached the spot, after which the girl was taken for a medical examination.A case was registered under the Protection of Children from Sexual Offences (POCSO) Act and relevant sections of the Bharatiya Nyaya Sanhita (BNS), including those dealing with gang rape of a person under 18, criminal conspiracy, voluntarily causing grievous hurt and criminal intimidation.Asif, a school dropout who worked at a vegetable shop, allegedly used to loiter in the park. According to the police, he had previously been involved in theft and snatching cases, including incidents in which firearms were allegedly used.Story continues below this adHe was arrested hours after the incident near the spot while travelling on a motorcycle, following a brief exchange of fire.Hemant and Mukesh were arrested from their house near the park, where they had been living for several months. Hemant is a law graduate, while Mukesh is pursuing a Bachelor of Science degree in mathematics.