Anjali Agarwal (42) and her 12-year-old daughter Kanika were beaten and stabbed to death at their apartment here on Monday night. The boy was missing since the incident.
The boy was traced in Varanasi and from there he was brought back to Noida. He has confessed to have killed his mother and sister, Bisrakh police station SHO Ajay Sharma said.
Asked about the motive of the crime, he said a probe is on and further details would be revealed in due course.
According to the examination report, the two were likely to have died between 8 pm and 11 pm on Monday.
More From This Section
A police investigation revealed the boy used to play a crime-gangster game on mobile phones. The game was found on other similar electronic devices in the house.
According to police, the boy was weak in studies and used to get scolded over his poor performance. On the day of incident too, his mother had scolded him over studies.