KOCHI: A 13-year-old girl and three teenage boys allegedly planned the murder of her 67-year-old grandfather in Kerala’s Alappuzha district to steal gold and money, with police saying the group intended to use the proceeds to buy an iPhone for the girl and a motorbike for her boyfriend.The girl’s boyfriend and two of his friends, all minors from Kollam, allegedly carried out the murder at her instigation, district police chief T K Vishnu Pratheep told reporters on Tuesday.He said the killing was carried out “in a professional manner, similar to what is seen in films.”Girl allegedly told boyfriend to kill grandfatherPolice said the group had two motives: to steal around 4.5 sovereigns of gold ornaments and to avenge restrictions the victim had imposed on the girl’s mobile phone use and friendships with boys.The girl had allegedly told her boyfriend that her grandfather had subjected her to “bad touch”, an allegation she had raised earlier, and that he needed to be killed.The victim lived with his wife, daughter and granddaughter at Haripad block panchayat in Alappuzha. On Thursday, his daughter, who was expecting a child, went to hospital accompanied by her mother.The murder took place on Saturday night after the girl allegedly told her grandfather that she needed to stay at a friend’s house to study for an exam and left.Teen boys allegedly entered house through ventilatorAccording to police, two of the boys, wearing gloves, entered the house through a rear ventilator opening and opened the front door to let the third accomplice in.They allegedly tied up the victim, beat him and smothered him on the dining room floor. Police said the girl watched the killing over a video call as it happened.A preliminary autopsy found smothering to be the cause of death.Before leaving, the accused allegedly took the gold ornaments and scattered chilli powder around the house to make investigators suspect a theft-only motive.Contradictions in girl’s statements unravelled alleged plotThe girl initially told police that she had visited the house twice on Sunday, knocked on the door and left after receiving no response. She said she then called her grandfather’s phone, which was engaged, informed her mother and returned to her friend’s house.She returned on Monday morning and, after again receiving no response, alerted neighbours. The victim was subsequently found dead inside the house, with his hands and legs tied with cloth.Police initially suspected close relatives and outsiders. However, contradictions in the girl’s statements, including a claimed alibi that did not hold up during questioning, led investigators to suspect her boyfriend and his friends.Cyber cell traces accused to Kollam within 24 hoursPhone records and other evidence helped police unravel her version within hours.Cyber cell investigators traced the accused to Kollam within 24 hours using mobile tower location data. Police said one ring from the stolen ornaments was sold for Rs 16,000 at a jewellery shop in Kollam, and the person who allegedly helped broker the sale has been identified.The remaining stolen gold was recovered by Tuesday morning, police said. The accused will be produced before the Juvenile Justice Board.Police attributed the alleged crime to a mix of cinematic influence and family problems. During questioning, the girl also told police that a lack of affection from her parents had weighed on her.