Activated by injustice, members of over-policed communities lead the current movement for civil rights in the United States. Responding to decades of abuse by law enforcement and an excessive criminal justice system, activists protested police brutality in Ferguson, organized against stop-and-frisk in New York City, and fueled the rise of Black Lives Matter. Yet, scholars did not anticipate this resistance, instead anticipating the political withdrawal of marginalized citizens. In Mobilized by Injustice, Hannah L. Walker excavates the power of criminal justice to inspire political action. Mobilization results from the belief that one's experiences are a consequence of policies that target people like one's self on the basis of group affiliation like race, ethnicity and class. In order to identify how individuals connect their experiences to a collective struggle, Walker centralizes the voices of those most impacted by criminal justice, pairing personal narratives with analysis of several surveys. She finds that the mobilizing power of the criminal justice system is broad, crosses racial boundaries and extends to the loved ones of custodial citizens. Mobilized by Injustice offers a compelling account of the criminal justice system as a spark for the formation of a movement with the potential to remake American politics.