Kambanda holds a degree in commercial engineering and began his career as a low-level United Popular BPR banker, rising as a technocrat to become the chair of the bank.
At the time of the April 1994 crisis he was vice president of the Butare section of the opposition Republican Democratic Movement (MDR).
Kambanda was arrested in Nairobi on July 18, 1997, after a seven-week multinational stakeout and transferred to the International Criminal Tribunal for Rwanda.
The court accused him of distributing small arms and ammunition in Butare and Gitarama with the knowledge that they would be used to massacre civilians.
According to the ICTR appeal: As a head of government convicted by an international court, Kambanda is an important figure, with the verdict against him forming a precedent against the legal principle of State Immunity (which was used to reject an extradition order for Augusto Pinochet, for example).