A engineering student along with her mother were found murdered in Saidapet apartment on Wednesday evening.
No valuable was missing from the ground floor flat and the jewellery the slain women wore was intact, police said.
Police identified the women as Hemalatha Shanmugam, a stenographer at Anna University, and her daughter Jayalakshmi Shanmugam final year student of Meenakshi Engineering College in KK Nagar. Hemalatha’s husband Shanmugam died last year in a road accident.
Hemalatha’s son Balamurugan, 25, a mechanical engineer employed at a private company in Sholinganallur on Old Mahabalipuram Road, is missing, police said.
Police suspect that committed by someone close to the family as there were no signs of forced entry to the flat.
Later police sources said that the boy was arrested and enquiry is going on.