The conflict erupted when police forces, alongside armed gunmen recruited from local farms, attacked a group of landless workers who were occupying an area of unproductive land.
Since 1985, local peasants in Rondônia had organized and created several communities, such as Alto Guarajús, Verde Seringal, Palmares do Oeste, Rondolândia, and later the town of Nova Esperança, which eventually became the city of Corumbiara.
The Special Operations Command, led by Captain José Hélio Cysneiros Pachá, deployed tear gas and spotlights against the families.
The bishop of Guajará-Mirim, Dom Geraldo Verdier, collected samples of charred bones from campfires at the scene and sent them to the Faculté de Médicine Paris-Ouest, which confirmed the cremation of human bodies at the camp.
The aftermath saw increased scrutiny of Brazil's land reform policies and the actions of both state and private forces in rural conflicts.
[4] In 2013, the Commission on Constitution, Justice and Citizenship (CCJ) approved a proposal to grant amnesty to both the landless workers and the Military Police involved in the massacre.