Ladislas Ntaganzwa was born in 1962 in Gasharu, in the Muhambara sector of the commune of Nyakizu (which is situated in the prefecture of Butare in Rwanda).
From 1993 until he fled Rwanda, he was Mayor of the commune of Nyakizu, a post which gave him authority over his subordinates, which included employees of the commune, members of the communal police, and counsellors from various sectors.
He was also head of the MRND party (National Republican Movement for Democracy and Development) in the commune of Nyakizu.
According to the indictment, Ladislas Ntaganzwa was reported to have participated in a plan to exterminate the Tutsi population in his commune from late 1990 until July 1994. Among other things, this plan included the fuelling of racial hatred and violence, the training and armament of paramilitary units, and the compilation of lists of people to be eliminated. In carrying out this plan, Ntaganzwa was alleged to have organized and ordered massacres and to have participated in them personally.
In the week following the death of President Habyarimana on 6 April 1994, Ntaganzwa was said to have organized a gathering of the population, during which he called upon them to eliminate the whole Tutsi population in the sector.
According to the indictment, Ntaganzwa distributed weapons to civilians on 15 April 1994, and accompanied them, together with members of the national police, to the parish of Cyahinda (commune of Nyakizu). People who had taken refuge from massacres in the parish were surrounded by these civilians and the police under the command of Ntaganzwa, who then asked them to give up everything that was in their possession.
Subsequently, Ntaganzwa was reported to have told the refugees to leave the parish and to return to their homes. When one of them tried to explain to him that they were afraid to do so, Ntaganzwa allegedly ordered his execution. He then gave the order to attack the others who had sought refuge in the church. Ntaganzwa was said to have taken part personally in this first attack, which caused several deaths and injuries.
On 18 April 1994, after a visit by interim President Sindikubwabo, during which he had called for the killing of more Tutsis, Ntaganzwa allegedly ordered and directed a massacre of the Tutsis who had survived the first attack.
Moreover, on 20 April 1994, he was alleged to have ordered and directed further killings accompanied by armed citizens.
Ladislas Ntaganzwa was indicted in 1996 by the International Tribunal for Rwanda (ICTR).