In this dissertation, I develop a socio-cultural framework for explaining anti-corruption crusades, understood as widespread efforts from investigative bureaucracies to investigate, prosecute, and convict corporate and political elites. Prior explanations typically focus either on factors exogenous to investigative bureaucracies, such as economic shocks and political will, or on organizational-level factors, such as the autonomy of prosecutors vis-à-vis politicians. My socio-cultural approach complements these accounts and is structured on two components: a focus on the group-level culture of prosecutors, which contrasts with prior studies that typically focus on cross-national or organizational-level analyses, and a socio-relational understanding of prosecutors and judges as embedded between State and society, in contrast with the predominant view that the Judiciary is insulated from civil society and in particular from social movements. This dissertation focuses on Brazil, leveraging different within-country comparative designs, as well as a mixed-methods approach that combines qualitative and quantitative data sources. Specifically, I draw on three distinct and original data sources: a) 130 in-depth interviews with judicial agents, b) an original dataset of appeals of corruption cases (N=1,136) constructed through supervised machine learning, and c) an original online experiment in which respondents were randomly assigned to watch videos that simulate a prosecutors' press conference where prosecutors use different frames when calling for public support (N=2,060). I argue that a socio-cultural approach to anti-corruption prosecutions contributes to existing accounts by 1) uncovering new causal drivers that were overlooked by prior studies, such as prosecutors' communication and decision-making practices at the group level; 2) highlighting the importance of looking at new outcomes, such as prosecutors' decisions to pay attention to some issues to the detriment of others; and 3) specifying the conditions under which already known causal drivers, such as prosecutors' outreach efforts, affect public attitudes toward corruption. In this way, my dissertation unpacks the work that prosecutors and judges do on the ground to criminalize corruption, and contributes to a more complete understanding of anti-corruption crusades.