They said the 32-year-old man was a tenant of the family and used to frequently pick up quarrels with the owner. After one such incident, he was asked to vacate the house.
He then rented a house some distance away and kept a watch on the movement of the family, they said.
The man reportedly went to the owner's house yesterday in his absence, picked up a quarrel with his wife, fished out a sharp weapon and attacked her, but it pierced the baby's stomach
The woman's husband spotted the bodies when he came home last night and informed police, who launched investigations and
Suspecting the role of the tenant, who had left for his native village Manamadurai, a special team rushed to the village, nabbed him and brought him back to the city for questioning,the sources said.