François-Xavier Nzuwonemeye was born on 30 August 1955 in Musasa commune in the prefecture of Kigali-rural, Rwanda. In 1993, he exercised the function of Commander of the 42nd Battalion. He was subsequently appointed Commander of the Reconnaissance Battalion within the Rwandan army. He held this post until July 1994. In this capacity, he exercised authority over all the units of this battalion.
Based on the indictment, from late 1990 until July 1994, Nzuwonemeye conspired with others to work out a plan with intent to exterminate the civilian Tutsi population and eliminate members of the opposition. The components of this plan consisted of, amongst other things, recourse to hatred and ethnic violence, the training of and distribution of weapons to militiamen as well as the preparation of lists of people to be eliminated. In executing the plan, he is said to have organised, ordered and participated in the massacres of the Tutsi population.
In order to implement the plan to exterminate the Tutsi and members of the opposition, the military and civilian authorities, from the end of 1992, distributed weapons to the militias and certain members of the civilian population. Due to the widespread availability of arms in the Kigali-town prefecture, UNAMAR (United Nations Mission for Assistance in Rwanda) set up a disarmament programme, known as “Kigali Weapon-Secure Area” (KWSA). This programme came into force at the beginning of 1994.
In order to avoid control by UNAMAR under its disarmament programme, Nzuwonemeye reportedly had several armoured vehicles and several jeeps equipped with machine guns of the Reconnaissance Battalion, hidden in Gisenyi and at the Presidential residence in Kiyovu. These armoured vehicles were used as early as the night of 6 April 1994, to reinforce roadblocks set up by soldiers and to surround the residence of the Prime Minister.
UNAMAR was perceived by certain Hutu extremists as an obstacle to their extermination plans. They therefore adopted a strategy aimed at provoking the Belgian military which had the most efficient and well equipped contingent in UNAMAR. Over time their objective was to force them to leave the country.
During the night of 6 April 1994, Belgian soldiers received the order to go to the home of the Prime Minister, Agathe Uwilingiyamana, in order to escort her to the National Radio where she was scheduled to make a speech. On arrival at her residence around 5 am, they were attacked by soldiers of the Rwandan Armed Forces (FAR), amongst which were units of the Presidential Guard, of the Para Commando Battalion and Squadron A of the Reconnaissance Battalion led by Captain Innocent Sagahutu under the command of Nzuwonemeye. They were subsequently disarmed and held prisoner together with five Ghanaian soldiers who were responsible for ensuring the safety of the Prime Minister. Despite having negotiated their surrender with a promise to be taken to a UNAMAR base, the Belgian and Ghanaian soldiers were taken to a camp in Kigali where they were attacked and beaten by Rwandan soldiers, including elements of the Reconnaissance Battalion led by Nzuwonemeye, and this in full view of officers of the Rwandan Army .Whereas the Ghanaian soldiers were set free, four of the Belgian soldiers were put to death on the spot. The six other Belgian soldiers held out against several attacks for a period of a few hours before finally being killed.
On leaving the Kigali camp site, Nzuwonemeye, was then said to have gone to the meeting at the Higher Military School only a hundred metres from there, whilst the attacks against the Belgian soldiers continued and after four of them had already been killed. He reportedly continued with his meeting until around noon. On 13 April 1994, in consideration of the death of 10 of its soldiers, Belgium decided to withdraw its contingent from Rwanda.
During the morning of 7 April 1994, the Prime Minister, Madame Agathe Uwilingiyimana was tracked down, arrested, sexually assaulted and then killed by elements of the Rwandan Army, in particular, those of the Presidential Guard. Nzuwonemeye was said to have ordered some of his soldiers to lend a hand to the Presidential Guard to assassinate the Prime Minister. Concurrently, members of these same units confined and killed important opposition leaders and prominent figures in the Tutsi community.
From April to July 1994, officers of the Army General Staff, one of which was Nzuwonemeye, participated in daily briefings at which they were informed of the massacres of the civilian Tutsi population and the moderate Hutu.
From April to July 1994, by virtue of their positions, their statements, the orders they issued and their actions, Nzuwonemeye, as well as General Augustin Bizimungu, General Augustin Ndindiliyimana, Major Protais Mpiranya and Captain Innocent Sagahutu, exercised authority over members of the Rwandan Armed Forces, their officers and militiamen. From 6 April 1994, these soldiers, gendarmes and militiamen, perpetrated massacres against the Tutsi population and the moderate Hutu and committed other crimes such as rape and sexual assault in addition to other crimes of a sexual nature, which were widespread throughout the entire territory of Rwanda and had the full knowledge of Nzuwonemeye, Bizimungu, Ndindiliyimana, Mpiranya, and Sagahutu.
From April to July 1994, in all regions of the country, members of the Tutsi population who were fleeing from the massacres taking place on their hillsides, sought refuge in locations they believed would be safe, often on the recommendation of the local civil and military authorities. In many of these places, despite the promise that they would be protected by the local civil and military authorities, the refugees were attacked, abducted and massacred by soldiers, gendarmes and militiamen often on the orders, or with the connivance, of those same authorities. Furthermore, in many of those locations, soldiers and militiamen abducted, killed and raped or sexually assaulted Tutsi women. François-Xavier Nzuwonemeye, in his capacity as, Commander of the Reconnaissance Battalion within the Rwandan Army knew, or had reasons to know, that his subordinates were about to commit or had already committed such crimes and did nothing to prevent these crimes or punish the perpetrators.
Knowing that massacres of the civilian population were being committed, the political and military authorities, one of which being Nzuwonemeye, took no initiatives or measures to stop them. On the contrary, they refused to intervene to control and appeal to the population as long as a cease fire had not been signed.
In July 1994, faced with the advance of the troops of the FPR (Rwandan Patriotic Front, an opposition movement composed essentially of Tutsi refugees and led by Paul Kagame), Nzuwonemeye fled Rwanda.
On 15 February 2000, he was arrested in Montauban in the south west of France.