The bombing, carried out by officers of the Brazilian Army, was a false flag operation intended to frame left-wing guerrillas as violent and thereby halting the country's transition towards democracy.

[6] The democratic cause in Brazil and all of Latin America was in part aided by U.S. president Jimmy Carter's promotion of human rights in his foreign policy.

[7] In 1974 the newly-inaugurated Ernesto Geisel administration moved away from the authoritarian repression of president Emílio Garrastazu Médici's government, and towards a restoration of Brazil's rule of law.

The interventionism and developmentalism that characterized the regime led to clashes during the Geisel administration (1974 – 79) between the nationalized industry sectors and the private multinationals, and divided the military into liberal and statist wings.

[8] These events pressured the military government to slowly begin a strategy to transition Brazil back to a democratic system, a process that is known in Brazilian politics as the abertura (opening).

[18] Throughout the evening of 30 April 1981, the Riocentro convention center in Rio de Janeiro's West Zone hosted a pop music concert organized by Centro Brasil Democrático to celebrate Workers Day.

[19] Over 20,000 people were in attendance, and the event was headlined by many famous MPB artists such as Moraes Moreira, Alceu Valença, Gal Costa, MPB-4, Beth Carvalho, Gonzaguinha, Elba Ramalho and Chico Buarque.

At Riocentro, operations manager Maria Ângela Lopes Campobianco reassigned Lt. César Wachulec from head of security to the tickets office, claiming he had issues with alcoholism.

At around 9:15 a bomb went off prematurely in the car, killing Army Sergeant Guilherme Pereira do Rosário, and seriously injuring Captain Wilson Luiz Chaves Machado.

Breaking news reports on the explosions on radio and television prompted relatives of concert attendees to drive to Riocentro in search of more information, leading to increased traffic and causing a commotion in the surroundings.

Marcondes Filho had attended the funeral of Rosário, who was buried with military honors, at the Cemetery of Irajá, and later arrived at Hospital Miguel Couto to visit Captain Machado.

PMDB secretary-general and Rio Grande do Sul Senator Pedro Simon expressed his fears that the terrorist violence would go unpunished and bemoaned the "incompetence of the government" in investigating it.

The document, kept in the National Archives in Rio, also describes the Figueiredo administration's actions to prevent a crisis by promising to publish results of the investigation and maintain the regular agenda to try and keep stories about Riocentro away from the news media.

[22] In April 2014 the National Truth Commission (CNV), established by the federal government in 2011 to investigate human rights violations from 1946 to 1988, released their report on the Riocentro case.

CNV concluded that military authorities were not only aware of the attack beforehand, but were also behind decisions to reduce policing that night, lock emergency exits at Riocentro and cover up the subsequent controversy.

[31] In 2014 five military men and a police chief were charged with first-degree murder and criminal conspiracy for their involvement in the operation, after renewed investigations by Federal Public Prosecution.