This book builds on Heffernan's last book Rights and Wrongs: Rethinking the Foundations of Criminal Justice by examining the class and racial disparities at the heart of current law — disparities that, according to many, generate a system of criminal injustice. It argues that these disparities run throughout the legal system; they’re present in policing, corrections, and sentencing. It discusses the relationship between the two kinds of justice — social justice and criminal justice and how to ensure fairness in state-imposed punishment. It theorises the extent to which criminal law must address considerations of social justice to ensure a fair system. It proposes a framework for analyzing disparities, provides an overview of contemporary research concerning them, and offers reform proposals for addressing them. Written in an accessible way, it introduces readers to philosophical theory and doctrines in constitutional law and thus it speaks to a wide audience concerned about racial and class disparities in the criminal justice system. It responds to a half-century’s worth of public concern about the legitimacy of the state’s exercise of its penal power while explaining the pertinence of social justice principles to the criminal justice system.