“Mass incarceration” has been a ubiquitous term in criminal justice circles because of the extraordinary number of people behind bars in the United States. Many partial solutions have been implemented on the state and federal levels, mostly concerned with sentence length and re‐​entry services for nonviolent offenders. Those changes have been improvements, for the most part, and have been life changing for thousands of inmates, returning citizens, and their families.

However, the fundamentals of our criminal justice system remain unchanged, and our policies continue to put too many people in cages for too long. The politics surrounding crime policy are often driven by fear and vengeance, not experience and data, and thus many jurisdictions are one tragedy — or a crime‐​rate increase — away from another wave of bad criminal laws. Our collective desire to punish wrongdoing through our criminal justice system too often outweighs the data that suggest better ways to improve public safety and reduce criminal recidivism.

In her new book, Prisoners of Politics: Breaking the Cycle of Mass Incarceration, Professor Rachel Elise Barkow provides a new conceptual framework for criminal justice policy. Barkow suggests new institutions and policies to provide oversight to prosecutors who currently have free rein over the most important aspects of criminal cases. She also proposes new expert bodies to collect and analyze data to formulate evidence‐​based crime policy to insulate policymakers from the populist whims that too often result in punitive laws and long sentences. In these and other ways, Barkow shows how our criminal justice system could reduce crime and roll back mass incarceration at the same time.