In 1969 founded with Isabel do Carmo, also a dissident of the PCP, the Revolutionary Brigades, an organization that defended armed struggle as a way to overthrow the fascist regime.
[6] Even before April 25, 1974, at a meeting in Milan, Carlos Antunes informed Joaquim Chissano, FRELIMO's leader, and later President of Mozambique, of divergences within the Portuguese Armed Forces regarding the continuity of the colonial war.
The BR became frustrated with the end of the revolutionary period and with the beginning of the consolidation of democracy and the preparation of Portugal's entry into the European Economic Community (EEC) and carried out a series of attacks and bank robberies.
After 25 November 1975, lawsuits were opened against Isabel do Carmo and Carlos Antunes as moral perpetrators of armed violence, being accused and placed in pre-trial detention in 1977.
[8] Within the Brigadas Revolucionárias the issue of the use of lethal violence and killings was something that had always been on the table and over time some BR members rebelled against the narratives of restraint that were defended mainly by Isabel do Carmo and Carlos Antunes.
[1] The imprisonment of Isabel do Carmo and Carlos Antunes proved decisive for the more radical faction inside the BR to move to deliberate killings.