In 1982, Sister Helen Prejean begins corresponding with a death row inmate at Louisiana State Penitentiary in Angola, Elmo Patrick Sonnier. Prejean has recently gone through a spiritual transformation and renewed her commitment to a life of social justice. As a result of this transformation, she has moved to the St. Thomas housing projects in New Orleans, where she witnesses crime and social inequality.
After exchanging several letters with Patrick, who has been convicted of the kidnap and murder of two teenagers, Prejean decides to become his spiritual advisor. During Prejean’s first visit with Patrick in Angola prison, Patrick tells her about his impoverished childhood and shares memories of his father and brother. After several months, Prejean also begins to visit Patrick’s brother, Eddie, who kidnapped and murdered the two teenagers along with Patrick and is serving a life sentence.
A judge sets Patrick’s execution date. Patrick says that on the night of the murders, Eddie lost control and killed the two teenagers. Eddie confesses to Prejean that he was the one who pulled the trigger. The U.S. Court of Appeals for the Fifth Circuit grants Patrick a stay pending a review of his petition but eventually denies it. Prejean contacts Millard Farmer, a death row attorney in Atlanta, to help with Patrick’s case. Millard agrees to help and prepares petitions for the Supreme Court and the Fifth Circuit. During a drive to Angola, he describes the history of capital punishment and the legal and political decisions that have shaped it. Millard paints a portrait of an arbitrary system that determines who lives and who dies primarily on the basis of race and class.
Millard appeals to Governor Edwin Edwards directly, but the governor has already decided against granting a stay based on political concerns. At the Pardon Board hearing, the chairman, Howard Marsellus (who will later be convicted of taking bribes in exchange for pardons), agrees with Millard and Prejean that the death penalty punishes poor men. While waiting for the board to make a decision, Prejean meets Lloyd LeBlanc, the father of one of the murdered teenagers. LeBlanc reprimands Prejean for not speaking to the victims’ families as well as to the killers. The Pardon Board votes in favor of Patrick’s execution.
With only four days left until Patrick’s execution, Eddie writes a letter to the governor confessing to the murder. Patrick is moved to the death house. On Patrick’s last day, Prejean encourages him to die with words of love instead of hate. The governor, Supreme Court, and Fifth Circuit all reject Patrick’s last appeals. Patrick has his last meal and talks fondly about his life. Millard Farmer and another death row attorney, Bill Quigley, arrive at the prison. Guards shave Patrick’s head and lead him out to the execution chamber. Prejean walks behind Patrick. Patrick apologizes to Lloyd LeBlanc for his crime and tells Prejean he loves her. At 12:15 A.M., the warden pronounces him dead.
With the help of Patrick’s family and the Catholic Church, Prejean buries Patrick. She helps raise money for a full-time death row attorney. For a time, Prejean believes she will never go back to death row, but on a spiritual retreat she decides she must continue to fight against capital punishment.
Prejean eventually agrees to become spiritual advisor to a man in his late twenties, Robert Willie. After learning that Robert brutally raped and murdered a teenage girl, Faith Hathaway, Prejean is briefly afraid of meeting him. Robert is eager for Prejean to visit him, but first Prejean has to convince the new prison warden that rumors of her emotional involvement with Patrick are false and that she does not represent a security hazard.
To raise awareness about the death penalty, Prejean has helped organize a three-day march from New Orleans to Baton Rouge. The march takes place shortly after Prejean meets Robert. In Baton Rouge, they meet a counterdemonstration. Vernon Harvey, Faith Hathaway’s stepfather, is at the demonstration and speaks to Prejean. The following week, Prejean visits Vernon and Elizabeth, Faith’s mother. They describe the details of Faith’s murder. Vernon cannot get past his overwhelming grief.
Prejean confronts Robert with his crime and asks him to think about the grief he has caused. He says he is sorry about what happened and blames the murder on Joe Vaccaro, his accomplice. Robert asks Prejean to look over the files he has prepared. Prejean reads about Robert’s long history of incarceration, his inadequate defense, and the clearly biased jury.
The Supreme Court and Fifth Circuit deny Robert’s appeals. At the Pardon Board hearing, Robert’s mother, Elisabeth, tries to testify but breaks down. Prejean asks the Pardon Board members not to participate in a system they know to be unjust. The Pardon Board rules against Robert unanimously. Howard Marsellus, the Pardon Board chairman, later describes to Prejean the corruption within the Pardon Board and apologizes for his participation in it.
As Robert’s execution date approaches, Prejean visits Robert every week. Major Cody, the man responsible for the death house, tells Prejean about the haunting effect executions have had on him. Robert is moved to the death house on Christmas Eve. He asks for a polygraph test; he wants to prove to his mother that he didn’t kill Faith. The test is inconclusive. Robert grants interviews to the press saying he admires Hitler and Castro and believes in the supremacy of the Aryan race. Robert visits with his mother, aunt, and stepbrothers for the last time on December 27. After his family leaves, he calls his mother and finally cries. He goes to the chair with his usual jaunty walk. With his last words, he tells the family of Faith Hathaway he hopes his death brings them comfort, but that killing is wrong.
After Robert’s execution, the Faith Hathaway’s parents give interviews in support of the death penalty. Prejean presents her arguments against it on ABC News and challenges the assertion that capital punishment can be a noble thing. She lists a number of men put to death for crimes they did not commit.
Two years after Robert’s execution, Prejean meets the Harveys, who are now advocates for victims’ families’ rights. Prejean helps found an organization, Survive, to assist victims’ families in the inner city. At one of Survive’s meetings, Prejean learns about the terrible treatment poor black women in the inner city have received at the hands of the district attorney and police. Prejean closes with a description of a prayer vigil she attends with Lloyd LeBlanc, the father of one of the murdered teenagers in the Sonnier case. LeBlanc says that even as he stared at his son’s corpse, he knew he had forgiven whoever had killed his son.