Crime is down in the United States, but incarceration has mushroomed. Some might argue this is proof of successful crime fighting. But more and more leaders and observers think the opposite: that these contrasting trends represent a critical disconnect and the failure of our justice system. Why has crime trended downwards, and what have we learned about the most effective strategies to prevent it? Why are so many people in prison? Who are they, and what landed them there? Explore the striking data and fateful policies behind our era of mass incarceration—and how we might change the problematic course we’ve been on.