<p>This article examines the decision of the Superior Court of Justice (STJ) in Recurso no Mandado de Segurança No. 70.411/RJ, which granted the family of Brazilian councilwoman Marielle Franco access to documents from the police investigation into her assassination. Marielle, a Black, lesbian woman from the favelas and a prominent symbol of resistance against racism and patriarchy in Brazil, was a human rights defender whose killing exposed Brazil’s structural failures in protecting those who challenge entrenched systems of violence left over from the colonial era. The case raised critical questions regarding Brazil’s compliance with international human rights obligations, particularly the standards established by the Minnesota Protocol, the UN Human Rights Committee’s General Comment No. 36, and the jurisprudence of the Inter-American Court of Human Rights (IACtHR) concerning victims’ rights and the duty to conduct effective, independent, and transparent investigations. Furthermore, it symbolized the enduring legacy of colonial domination and its contemporary expression through necropolitics. Methodologically, the article conducts a qualitative analysis of the STJ ruling, exploring how international instruments were invoked to justify victims’ participation in criminal investigations and to reinforce the diffuse control of conventionality within the Brazilian legal system. The discussion highlights the structural obstacles that continue to hinder accountability in cases involving state and parastatal violence in the Global South context, assessing whether the decision constitutes a meaningful institutional shift. Ultimately, the article argues that the ruling represents an important, though limited, step toward aligning Brazil’s investigative practices with international standards and strengthening the protection of victims’ rights in contexts of human rights violations.</p>