Colonel Theoneste Bagosora has been sentenced to life in prison for his role in masterminding the 1994 genocide in Rwanda.
As the cabinet director in Rwanda's defence ministry at the time, Theoneste Bagosora, 67, was an extremely senior member of the extremist Hutu regime behind the killings.
Bagosora is the first person to be convicted by a UN-backed international tribunal of organising the massacre in which more than 800,000 Tutsis and moderate Hutus were killed in just 100 days.
According to prosecutors at the International Criminal Tribunal for Rwanda, the extremist Hutu committee began its planning as far back as 1990.
The following year, they helped draft a document circulated within the army that described Tutsis as "the principal enemy".
Rwanda has a long history of conflict between the majority Hutus and minority Tutsis.
On 6 April 1994, a plane carrying the president of Rwanda, a Hutu, and the leader of neighbouring Burundi, was shot down over the Rwandan capital Kigali.
It is still a mystery who shot down the plane, but the event was to be the catalyst for the genocide.
Later that night, the colonel is said to have called senior military officers to the Rwandan army headquarters to mount what was effectively a military coup against what remained of the country's civilian government.
The slaughter began almost immediately, carried out by the government army and associated militias.
Members of the Interahamwe Hutu militias set up roadblocks, where anyone identified as a Tutsi by their national ID card was killed - often hacked to death on the street with a machete.
Other units systematically killed people - moderate Hutus, as well as Tutsis - on a list of those seen as enemies of the extremist Hutu government.
Bagosora is accused of distributing the guns and machetes that became the chief tool of the genocide.
The colonel denied all the charges.
During the trial, his lawyer challenged the very basis for the case, arguing that prosecutors failed to prove that the slaughter was organised and therefore failed to prove that it met the legal definition of "genocide".
"I never killed anybody, neither did I give orders to kill. You are the ones who can rehabilitate me back to the society," Bagosora told the court.
He maintained he was a victim of propaganda by Rwanda's current Tutsi-dominated government.
'Shaking hands with devil'
Before the killings, Bagosora was accused of storming out of 1993 peace talks in Tanzania with then Tutsi rebel leader Paul Kagame, now Rwanda's president, and saying he was returning to Rwanda to "prepare the apocalypse".
Canadian General Romeo Dallaire, head of UN peacekeepers in Rwanda at the time, described Bagosora as the "kingpin" behind the genocide.
He wrote in his memoirs that the colonel was a "known extremist" who "controlled - as well as anyone could - the genocidal militia".
It was the colonel who introduced the militia leaders to Gen Dallaire when the UN commander thought it might help save lives to meet them.
After talking to the militia leaders, one of whom had blood stains on his shirt, Gen Dallaire wrote that he felt he had "shaken hands with the devil".
At their last meeting on Rwandan soil, in 1994, the Rwandan colonel reportedly said that the next time he saw the Canadian general he would kill him.
He never did. Shortly after that meeting, Bagosora fled to Cameroon, where he remained in exile until his arrest in 1996. He was then detained until his trial in Tanzania in 2002.
The next time the pair met was in court, where Gen Dallaire testified for the prosecution.