The robbers entered the house around 2.30 am Thursday by cutting the grill of one of the windows. While retired lawyer and former director of prosecution SK Dutta and his wife were tied and gagged, their unmarried son Animesh was killed by robbers.
Animesh is suspected to have been killed for putting up resistance. As there were no injury marks on the body, police believe that he was smothered to death.
Police said that valuables and cash were missing from the house. The CCTV footage of the area where the house is located is being examined.