A preliminary inquiry suggested that tensions within the family played a role in the attack. Police said the teenager, who dropped out of school after Class IX and was unemployed, had been pressuring his father to hand over a family-owned shop to him. When his father refused, police believe, he became resentful towards his elder brother. “The boy feared that his father would eventually give most of the family’s property to his elder brother,” a senior police officer said. “Based on the inquiry so far, this appears to have been the motive behind the killings.”

According to police, they received information in the early hours of Monday that a teenage boy had allegedly killed three members of his family and locked himself up on the first floor of the house.

A police team rushed to the scene and found the first-floor door locked from the inside. After repeated attempts to persuade the teenager to open the door failed, an officer climbed the exterior wall to gain access to the floor, and the teenager was taken into custody, police said.

Police said the preliminary probe revealed that the boy entered his elder brother’s room around 3 am and attacked his brother, sister-in-law, and their son. The couple’s nine-year-old daughter was sleeping in the same room and woke up during the crime, police said. She ran out of the room, and her screams woke up the other family members. They rushed into the room to find the three bodies. The teenager then fled to the first floor and locked himself up till the police arrived. Police said they are also probing if the teenager is suffering from mental health issues.