Newly-married Kanchan was poisoned to death on September 14, 2011 in Baghauta village of Bansdeeh area here and her body was stuffed in a box, prosecution said.
On a complaint filed by the brother of Kanchan, dowry death case was filed against her husband Mukesh, mother-in-law Dharmsheela and father-in-law Ravindra.
After hearing both the sides, Additional District Judge DPN Singh yesterday convicted and sentenced the three accused.
A fine of Rs 10,000 each was also slapped on them, prosecution said.