In 1984, eight-year-old Paula Logares was called into a judge’s chambers and was told the man and woman she lived with were not her parents. Her parents had been disappeared during the dirty war, and now, through her blood, scientists would be able to return her to her birth family. Paula, thus, became the first "stolen" child in Argentina to be identified via the incipient technology of DNA identification. With this forensic first, DNA identification has emerged as a central tool of good governance the world round. From routine crime fighting to international criminal tribunals, DNA plays a crucial role in attempts to reckon with crimes of the body. As an alternative origin for forensic DNA, Argentina offers an early example of science emerging from social movements in the Global South. Drawing on twenty-seven months of fieldwork with family members, activists, and scientists, this article documents the ways in which DNA has emerged as a core site of subject formation for individuals and families affected by the terror of the dictatorship and for the Argentine nation-state, as it reckons with the legacies of repression. Through a feminist, postcolonial frame, I offer the concept of re(con)stitution as a way of attending to the forms of biocitizenship that emerge during times of humanitarian crisis and transitional justice. As a tool of reproductive governance, forensic DNA acts not only as a powerful disciplinary site of biocitizenship but also as a potential space to reimagine the social contract between the body, the public, and the state.