The Ways of Evil Men

As Chief Inspector Mario Silva has learned, justice is hard to come by in Brazil, so when his niece tells him about a possible genocide deep in the jungle, he agrees to round up his team and charter a plane to Pará to check it out. Thirty-nine natives have recently dropped dead of mysterious causes. Given the tense relationship between the Awana tribe and the white townsfolk nearby, Jade Calmon, Pará's sole government-sponsored advocate for the native population, immediately suspects foul play and takes the two remaining Awana-a father and his eight-year-old son-into her custody.
But when the father is discovered holding a bloody machete next to the body of a village big-shot, just before Silva's arrival, the plot thickens. Why would a peaceful man who doesn't believe in alcohol turn into a drunken killer?