According to prosecution, Stephen Selvaraj and the woman, a Home Guard in a local police station, were living together after he promised to marry her.
However, later he refused to marry her and upset over this, she committed suicide by consuming poison in July 2007.
Police registered cases under IPC sections 376 (punishment for rape) and 417 (punishment for cheating) against him.
District Mahila Court Judge Krishnan awarded life imprisomnent to the constable.