The massacre was carried out from July 15-20, 1997, by the United Self-Defence Forces of Colombia (AUC), an outlawed right-wing paramilitary group.

On July 12, 1997, two planes containing paramilitary members arrived at the airport of San José del Guaviare, which also served as a base for the anti-narcotics police.

[3][4] In proceedings before the Inter-American Court of Human Rights, the government of Colombia admitted that members of its military forces also played a role in the massacre, through omission.

[5] General Jaime Uscátegui allegedly ordered local troops under his command to stay away from the area in which the murders were taking place until the paramilitaries finished the massacre and left.

[11][10] On November 25, 2009,[10] the Bogotá superior tribunal announced in a ruling of ninety pages that it had passed a forty-year prison sentence on 61-year-old General Uscategui.