The 75 year old Lakshmi and Ayyammal (65) were found strangled, one in the toilet outside their house and another within the residence at Udayampalayam yesterday morning, with cash and ornaments missing.
Suspecting that this could be the handiwork of persons known to them, police conducted investigations and nabbed a man who married the 65-year-old woman's grand daughter
On being questioned, the man confessed that he and his mother had poisoned both women to death and later strangled them to confirm they were dead, police said.