This much is clear: When California voters approved Proposition 89 in 1988, thus granting the governor authority to reverse decisions made by the Board of Parole Hearings on parole-eligible murderers, paroles in these cases almost ceased to occur. At a cost to the state of $50,000 to $100,000 per inmate per year, former governors George Deukmejian, Pete Wilson, Gray Davis and Arnold Schwarzenegger reversed the board's decision to parole in a vast majority of cases.

What's less clear, and what Nancy Mullane wants us to consider, is what this situation has meant for the prisoners. Through claustrophobia-inducing descriptions of prison cells and sobering reports of how a prisoner who has been incarcerated more than 20 years actually conceives of freedom ("What's the first thing you want to do when you get out?" "Take my shoes off and then take my socks off and walk on the carpet. Then I want to go to the store and buy all different kinds of salsa."), Mullane reveals how little we know about what life is like for long-term prisoners, and reminds us how significant this is.

As Kim Richman, professor of sociology and legal studies, is quoted in the book, "Responsible human beings should understand the living conditions of their fellow human beings. That requires a leap, because it requires you to see people inside prisons as humans, which most people don't." Reading "Life After Murder: Five Men in Search of Redemption," we have no choice but to do so.

Spending time around murderers, Mullane proves our proxy as she encounters her own ignorance and judgmental tendencies and slowly replaces fears and preconceptions with understanding and compassion. It's the relationships Mullane builds, and the stories she tells -- particularly those of the five paroled murderers who compose the central focus of the book -- that move the book beyond policy analysis and into something profoundly human. These five are willing to go public with their crimes because, as one murderer says to Mullane, "If by my telling my story it will make it possible for my brothers who are still locked up to get out, I'll answer any question you've got."

Their stories are complicated and compelling. When these men meet obstacles, as they surely do, you will be shocked by your desperation to turn the pages and learn that things work out for them. They do, and they don't.

Because this is not a book of suspense, I don't mind revealing the surprise happyish ending, policy-wise. In 2008, the California Supreme Court ruled that a governor must have "current evidence" of a prisoner's threat to society to deny parole. Since beginning his second term in 2011, Jerry Brown has reversed only 17 percent of the parole board's decisions. As more murderers who deserve to be released are released, the stories in "Life After Murder" become increasingly important to help us understand this oft-ignored segment of our population.

Scott F. Parker's books include "Revisited: Notes on Bob Dylan," "Running After Prefontaine: A Memoir" and "Coffee: Grounds for Debate." He lives in Minneapolis.