Those who are familiar with America’s criminal justice system are cognizant of the statistics swirling around the nation’s dependence on prisons and jails as a crime control policy. The United States boasts 2.2 million adults behind bars, housing more inmates than any other country. Currently, one of every 100 adults in the United States is in prison or jail. And incarceration rates have more than quadrupled in the past four decades. Current rates of incarceration reflect an unprecedented use of prison as a tool in combating crime.

Statistics are what they are. Merely numbers without a face, they can be seen as additional prison beds that need to be built and more correctional officers who need to be hired. But they don’t tell a complete story, and they make it possible for policymakers, judges, and others who work in the criminal justice system to ignore the harsh realities of what it feels like to spend time in America’s prisons. Jonathan Simon, a law professor at the University of California, Berkeley, explores the policies that led to today’s mass incarceration levels through telling the story of a succession of prison condition challenges in California’s courts. In his new book, “Mass Incarceration on Trial: A Remarkable Decision and the Future of Prisons in America,” Simon examines the 2011 U.S. Supreme Court case Brown v. Plata as a lens into the country’s larger dependence on mass incarceration as a crime control policy.