MUMBAI, Oct. 21 -- Four days after 18-month-old Ariba Khan died when she fell from the sixth floor of a Mhada building in Goregaon East, the Dindoshi police on Monday booked a 10-year-old girl residing in the same building for murder, as CCTV footage indicated that she had "deliberately pushed" the toddler into the duct beside the elevator, resulting in her death. On Tuesday, the 10-year-old girl was produced before the Juvenile Justice Board, which handed her custody back to her parents in view of her age, until further orders. According to the police, the incident occurred around 9.30pm last Wednesday, when Ariba was playing with a cat outside their flat on the sixth floor of building no. 1 in Anjuman Society, Goregaon East. When her mother was unable to find her, she asked her son and Ariba's elder brother to look for her. The boy peeped through the railing and saw his sister lying on the ground floor, bleeding. He ran down and raised a cry for help, following which building residents informed the family and rushed the injured Ariba to hospital, where she was declared brought dead. After doctors at the hospital informed the police, they conducted a panchnama and sent the girl's body for post mortem, which revealed that she had died due to injuries sustained from the fall. The police initially registered an accidental death report in the case. But when they reviewed CCTV footage from the building's lobby on the sixth floor, they saw the 10-year-old girl gesturing to Ariba, calling her towards the elevator. Ariba was then seen approaching the spot, and the 10-year-old was seen grabbing her, as they went outside the purview of CCTV cameras. Based on the footage, police suspected that the 10-year-old girl had pushed Ariba over the retaining wall around the duct beside the elevator, causing her to fall from the sixth floor to the ground floor. On Monday, they booked the girl under section 103 (1) (murder) of the Bharartiya Nyaya Sanhita, based on a formal complaint by Ariba's mother and relevant CCTV footage. Ariba's aunt Gulnar Sayyed said that the toddler's father, Shakir, was a driver. The family had moved into flat number 602 on the sixth floor around a fortnight before the incident, and they were not acquainted with any of the neighbours, she mentioned. "After the funeral of my niece, we checked the area around the elevator duct and suspected foul play, as the height of the protective wall around the duct was around 3.5 feet, which was too high for a toddler to climb over and fall," Sayyed told Hindustan Times. The accused girl was produced before the Juvenile Justice Board on Tuesday and sent back to the custody of her parents in view of her age. "She will now have to undergo counselling sessions as per the board's instructions," a police officer said, requesting anonymity. Section 20 of the BNS grants complete immunity to children up to seven years of age, saying, "Nothing is an offence which is done by a child under seven years of age". Section 21 of the BNS grants "limited immunity" to children aged 7-12 years, saying, "Nothing is an offence which is done by a child above seven years of age and under twelve, who has not attained sufficient maturity of understanding to judge the nature and consequences of his conduct"....