Third Additional Sessions Judge Balakrishnan sentenced the woman to life imprisonment yesterday.
The prosecution case was that the woman's 20-year-old son, a hosiery worker at a unit in Tirupur had married a girl of another caste without his mother's knowledge
On March 28 2014, he came to his mother's house at Nanjagoundenpalayam and stayed there. That night, she smashed his head with a stone and he died on the spot.