New Delhi, Nov. 14 -- Delhi Police filed a 450-page charge sheet on Friday against three men accused of gangraping a 17-year-old girl at Aastha Kunj Park in south Delhi in September, detailing how they allegedly impersonated police officers, intimidated the teenager and her friend, and assaulted her at knifepoint. The charge sheet, accessed by HT, names Md Asif, Hemant Singh and Mukesh Singh and includes statements from 57 witnesses, CCTV footage, call records and forensic evidence. According to investigators, the girl and her 17-year-old friend visited Kalkaji Temple on September 21 before going to the 143-acre park, managed by the Delhi Development Authority. They were sitting on a bench around 7pm when three men questioned their presence and claimed to be policemen. The accused allegedly slapped the boy, took both teenagers' phones and threatened the girl with a firearm when she asked to call her mother. They then separated the two, taking the boy to another part of the park, before allegedly sexually assaulting the girl while threatening her with knives. The teenager identified the accused during the investigation and recalled nicknames she had overheard during the assault. Her statement is a key part of the prosecution's case. The charge sheet cites CCTV footage showing the suspects near the park, including the evening of the alleged crime. Police used call detail records to place them in the area and establish that Asif contacted the other two during the incident. Police recovered clothes believed to have been worn by the suspects, weapons, a motorcycle allegedly used to flee, and material collected from the scene. The charge sheet refers to forensic findings involving biological samples and data recovered from mobile phones. Asif was arrested on September 22. Brothers Hemant and Mukesh were arrested at their Sri Niwaspuri residence. All three have been charged under provisions of the Bharatiya Nyaya Sanhita relating to gangrape, criminal conspiracy, causing hurt and criminal intimidation, and Sections 6 and 17 of the Protection of Children from Sexual Offences Act....