What does it mean to trust in a world shaped by violence and inequality? This book investigates the fraught pursuit of democratic policing in Brazil, where trust is both a necessity and a precarious gamble. Marta-Laura Haynes follows police officers and favela residents through patrols, crime scenes, fishing trips, drumming circles, and neighborhood gatherings to reveal how trust is not simply given or earned--but actively performed, negotiated, and also refused. These stories show how trust intersects with local ideas of citizenship, legitimacy, race, and power while also exposing the pervasive and often generative role of mistrust. Far from being a stable foundation for democracy, trust in this context is a high-stakes wager, shaped by local hierarchies of race, gender, and class. In response, communities develop what Haynes calls "untrusting": a mode of engagement that refuses blind faith in the state and instead turns mistrust into a form of care, resistance, and survival. By illuminating the contradictions and complexities of trust in Brazil, Untrusting challenges reductive narratives of policing and offers a nuanced perspective on how democratic ideals are contested and reimagined by people on the ground. Challenging the idea that distrust is merely a barrier to progress, Haynes shows how it can be a resource for agency, dignity, and alternative visions of justice.