Two days after the decomposed bodies of an elderly couple were found inside their flat in south Delhi’s East of Kailash, police on Monday said they were murdered by their masseuse’s 17-year-old son on January 18.Police said they have apprehended the boy and arrested his 50-year-old mother, who was in the couple’s employment for seven years, in the case. The motive for the murder, police said, was robbery.After 77-year-old Virender Kumar Khaneja and 72-year-old Sarla Khaneja were found dead, with the woman’s hands bound, inside their locked house with no sign of forced entry or ransacking, police initially suspected that it may have been a suicide pact. However, as Hindustan Times reported earlier, a few questions had remained answered — why did the masseuse not inform anyone after the couple failed to answer her knocks for around a week, and why the safety latch of an entry door was unlatched. Also, after January 18, there was no CCTV footage of the masseuse coming to the complex, police said.These, an investigator had said, prompted them to suspect her.Questioning of the masseuse and CCTV footage from Mount Kailash apartments, where the couple lived on the ninth floor, led them to suspect that the teenager committed the murder.Deputy commissioner of police (southeast) Chinmoy Biswal said the 17-year-old spent almost 24 hours inside the flat, during which he killed the couple, stole cash and jewellery, and made several arrangements to pass it off as suicides.“The questioning of the juvenile led to the recovery of around Rs 9 lakh in cash, jewellery, camera, wallet, the couple’s phones, and other valuables from his Sangam Vihar house,” said Biswal. “The masseuse told us that a few days ago, she had seen a lot of cash in the couple’s house and planned the robbery with her son. Her police verification was done by the apartment’s resident welfare association in 2017.”Police said that CCTV footage from the apartment complex prompted them to probe the role of the masseuse and her son. The woman and son were questioned and confronted with evidence after which they admitted to the crime, said police.On January 18, a police officer associated with the case said, the masseuse reached the couple’s flat for work around 11am and deliberately left both doors to the flat — an iron and wooden one — open. Her son arrived around 11.30am and discreetly entered the flat. The teenager allegedly hid himself in one of the bedrooms, while his mother left the home around noon.Around 2.30pm, dressed in his formal suit, Virender Khaneja went out for some work and Sarla locked the door after him.“Around half-an-hour later, the juvenile went to her bedroom and overpowered her,” said the officer. “He tied her hands with a cloth and demanded to know where the cash and valuables were kept. When she told him that only her husband knew where they were, he strangled her using another cloth and left her there,” said the officer.Around 8.30pm, Virender returned. When his wife did not respond to the doorbell and his phone calls, he let himself in using a spare key.“The teenager overpowered him and threatened to kill him if he refused to tell him the location of cash and jewellery,” the officer said. “The man panicked and gave him the keys to the cash box. The boy then strangled Virender. Both bodies were found on either side of the bed in the bedroom with some naphthalene balls around them. The teenager spent the night in the flat and left with the cash and jewellery the next morning.”The boy allegedly also made away with jewellery from the woman’s body.Next day morning, the boy was seen on CCTV leaving the flat with a trolley bag that contained cash and other valuables, the police said.The boy allegedly also told police that he stole the couple’s mobile phones in the hopes of using their bank cards and the one-time password to withdraw money.“We are waiting for the couple’s autopsy reports to ascertain the exact cause of deaths. The teenager told us that he killed them because they knew him and he feared that sparing them would led to his arrest. His claims are being verified,” said Biswal.The couple had been registered in the Delhi Police’s programme for senior citizens, which included regular visits from the police to check on their safety. Their bodies were found on January 26 after their distant relative from Gurugram called the police control room and informed them that the couple was missing and their phone numbers unreachable.