( CNN ) -- A former mayor in Rwanda has been convicted of genocide and extermination as a crime against humanity over the deaths of 2,000 Tutsis during the country 's 1994 genocide , the U.N.-backed International Criminal Tribunal for Rwanda said Thursday . Former Kivumu mayor Gregoire Ndahimana served as a leading facilitator and commander in the slaughter of Tutsis in Kivumu , where an estimated 4,000 Tutsis were murdered , according to the ICTR 's Summary of Judgment . According to the judgment , Ndahimana was present during a massacre at the Nyange Catholic church where 2,000 Tutsis died over 10 days from 6 April 1994 to 16 April 1994 , in one of the bloodiest sites of the genocide . His presence `` had an encouraging effect on the principal perpetrators , '' particularly because he was an authority figure , the tribunal found , ruling that he `` aided and abetted genocide . '' Ndahimana was also found guilty of `` extermination as a crime against humanity by aiding and abetting as well as by virtue of his command responsibility over communal police in Kivumu , '' the judgment said . Ndahimana was sentenced by a majority of the Trial Chamber 's three-judge panel to a single sentence of 15 years imprisonment , the ICTR said , with credit for two years already served . `` The Chamber has considered the gravity of each of the crimes for which Ndahimana has been convicted , '' the judgment said . Gruesome reports by survivors and other witnesses accused Ndahimana of joining local police and a priest in ordering assailants to bulldoze Nyange church , killing 2,000 Tutsi refugees who had sought sanctuary there . A majority of the judges ruled that Ndahimana was present during the demolition of the church , but did not find it proven that he instigated or supervised the attacks . A trained agronomist , Ndahimana served as `` bourgmestre '' of Kivumu , a commune in the prefecture of Kibuye near Lake Kivu . According to a United Nations study , at least 59,050 people , or 12.4 % of the Kibuye population , were killed during the genocide , accounting for more than three-quarters of the prefecture 's Tutsi population . The Rwandan genocide was triggered by the April 6 , 1994 , shooting down of a plane carrying the nation 's Hutu president . Ethnic violence erupted and Tutsis were killed systematically by Hutus over the course of three months . The United Nations estimates that some 200,000 people participated in the perpetration of the Rwandan genocide . In all , some 800,000 men , women , and children -- mostly Tutsis but also moderate Hutus -- died .
Gregoire Martin was mayor of Kivumu at the time of the 1994 genocide . He was accused of involvement in a massacre at a site in which 2,000 people died . The judges found him guilty of planning and abetting genocide and extermination . Some 800,000 people , mostly ethnic Tutsis , were killed in the six - month bloodletting .