This article examines the junction of state healthcare and punishment through HIV criminalization. By problematizing the application of criminal law to HIV in Finland, the study locates a genealogy of the “infectious criminal” – a figure at the cusp of these two forms of state power. The article traces how this figure, evoked in official debates from the early 20th century onwards, justified punitive measures to control marginalized people, from poor merchants to prisoners-of-war, sex workers, vagrants, and later, migrants. Drawing on parliamentary archives, the article asks how punishment and existing social injustices are narrated, maintained, and connected. Revealing a continuum of punishment and healthcare, HIV criminalization – especially within a nation deemed exceptionally non-punitive and welfare-oriented – is a crucial point from which to examine the connections of social injustice and criminal justice.