Special Court judge Ajay Singh convicted and awarded life sentence to Tulsiram, who worked as a cook at Chechat police station of the district, for raping and killing the woman constable on the night of September 29, 2010.
Another accused - Deshraj, constable at the time of the crime, was acquitted due to absence of evidence against him.
The body of the woman constable was found inside a room in women's guest house of Chechat police station a day after the incident.