Mujyabwami is accused of planning the genocide, participating in missions which massacred Tutsis in Kamembe and Gashirabwoba, and distributing weapons. He has pleaded not guilty, which excludes him from Work of General Interest (WGI) and the possibility of a suspended sentence.
Mr Biniga's accomplices, Victor Habineza, Damascene Nzacahayo were sentenced to 25 and 30 years in prison respectively.
Biniga was apprehended last year in Goma (DRC) while he was on a business trip.
The Gacaca courts are not presided by professional judges but by persons who are of high esteem in the society.
© Hirondelle News Agency