Sessions Judge B K Chetry sentenced Dandeswar Barman for raping and murdering the 12-year old class six student in July 2005.
Barman, a resident of Gasbari area of Goreswar town of the district, was found guilty of raping and killing the class six student of Gasbari High School.
The 50-year old married man and neighbour of the girl entered her house when her parents were away and committed the crime.
He was arrested immediately after the incident.