Pallavi (25), daughter of IAS officer Atanu Purkayastha, was found murdered at her 16th floor apartment at the upscale Himalayan Heights building in suburban Wadala on August 8.
Police soon zeroed in on Sajjad Mughal, the building's watchman, who was arrested while allegedly trying to flee.
He was charged with murder and trespassing. Initially he had been charged with molestation too, but the charge has been dropped now.
Earlier, the police had said that Mughal (22), a native of Uri in Baramulla district of Jammu and Kashmir, stole the keys to the flat and entered when she was alone at home, tried to rape her, and stabbed her to death when she put up a fierce resistance.
The charge sheet contains statements of 45 witnesses.
