Every bitter thing

The son of the Foreign Minister of Venezuela is found dead in his apartment in Brasilia. Due to the political nature of the crime, Chief Inspector Mario Silva of Brazil's Federal Police is called in to investigate. As he delves deeper into the murder, he discovers that a chain of murders have occurred throughout Brazil, all with the same MO: victims are first shot in the stomach, then brutally beaten to death, and, even more puzzling, they were all passengers on TAB flight 8101 from Miami to São Paulo. What sinister motive connects these killings? And why does it appear one passenger on that…