New Orleans, Louisiana (CNN) Sister Helen Prejean blasts the air-conditioner in her champagne-colored Toyota Corolla, the back bumper held up with duct tape. It's clear why friends insist on driving when they are with her. She could rival NASCAR's Danica Patrick on the gas pedal. Age -- she turned 75 this year -- hasn't slowed her down.

She was weaving all over Interstate 10 when police stopped her one time. Turned out she was reading while driving. The officer let her go when he discovered who she was: "I'll go straight to hell if I ticket a nun," he said.

He made her promise she would never do that again.

These days, she depends on iPhone's Siri for driving directions and making phone calls. She also likes to play "Plants vs. Zombies" (not while in motion, of course) even though the violent nature of the game goes against her Christian principles.

"It's OK," she says. "The zombies are already dead."

On this day in late July, Prejean is nearing Louisiana State Penitentiary, otherwise known as Angola, for the post office that serves it. She's been here so many times the warden no longer subjects her to the protocol for visitors.

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She drives down State Highway 66, through the guarded gates, past lush green cypress trees and fields brimming with flowers, okra and collards to Camp F, where the prison constructed a $9 million brick building to lock up the condemned.

Built on a former slave plantation surrounded on three sides by the Mississippi River, Angola is the nation's largest maximum-security facility. It houses more than 6,000 inmates and encompasses a chunk of fertile Southern farmland almost the size of Manhattan.

Prejean is here to see Manuel Ortiz, convicted in 1992 of the murders of his wife, Tracie Williams, and her friend Cheryl Mallory. He's been on death row for more than two decades; Prejean began visiting him 13 years ago.

Ortiz maintains he was framed in a murder-for-hire scheme. Prejean believes his claim of innocence . But that is almost beside the point.

Prejean, who gained fame as a death penalty abolitionist after the movie "Dead Man Walking" hit theaters in 1995, is not always concerned with a convicted murderer's guilt or innocence. It's easy to forgive the innocent. It's the guilty, she says, who test our morality.

She ministers to the worst of humanity because she believes in the restoration of life and that every human being deserves to be treated with dignity.

That is what Jesus preached. She likes to say that Christ was more radical than Karl Marx in his embrace of the lowest rungs of society.

Three decades ago, Prejean embarked on a mission to end the death penalty based on her Catholic faith and belief in human rights. The Universal Declaration of Human Rights, she says, forbids torture and cruel, inhuman and degrading treatment or punishment.

Ministering to death row inmates and learning the intricacies of American criminal justice, Prejean arrived at another steadfast belief: The process is broken.

Outside the entrance to death row, there's a porch with three dark wooden rocking chairs. The warden, she thinks, could have had a career in decorating the way the place is all fixed up.

A prison staffer leads her into one of the booths reserved for lawyers who come to meet with their clients. She sits on one side of the thick glass with a phone in her hand.

Ortiz walks in on the other side with leg irons, handcuffs and a chain around his waist. He always feels cold when he comes out of his 6-foot by 10-foot cell on death row. It's not air-conditioned and has louvered windows. A federal lawsuit filed by three inmates claims the heat index has reached 172 degrees.

The first thing Prejean does is order food for Ortiz from prison concessions; otherwise he will have to eat the normal slop that is served in the cells and never contains anything fresh.

"It's part of the attitude here. You committed a crime so you must always suffer," Prejean says.

Helen Prejean visits Manuel Ortiz on Louisiana's death row. She believes he is innocent.

She knows Ortiz does not have the money to buy anything. And food is important to her. It is the most basic necessity of life; it should be celebrated when shared with family and friends, she says.

Ortiz wants a catfish Po' Boy, a roast beef Po' Boy, five bags of potato chips, two Cokes and two Sprites. He also orders four strawberry and two cinnamon Danishes for breakfast the next morning and two hamburgers for lunch because Prejean has some money left.

She orders a grilled cheese for herself. She and Ortiz pray together.

"You are a son of God," she tells death row inmates. "Christ is with you. What is being done to you is wrong. I will be there for you."

Prejean finds Ortiz in high spirits on this day. With her help, he recently changed lawyers because he felt he wasn't being heard. He is desperate to prove his innocence and filed for FBI documents pertaining to his case through the Freedom of Information Act.

Ortiz dreams about the day he might walk out of Angola. He dreams of taking Prejean to one of the volcanic lakes in his native El Salvador. He wants to teach her to scuba dive.

They talk about everything from Marco Polo to J. Robert Oppenheimer's invention of the atom bomb. The science was so sweet; the end result, ghastly.

In the last hour of their visit, Ortiz narrates the plot lines to movies he's seen recently: "Band of Angels" with Clark Gable and "The Girl With the Dragon Tattoo."

"I feel like I've seen the movies now," Prejean says.

It's as though they were sitting on a couch in someone's family room, sipping a cocktail -- Prejean loves her single malt Scotch -- and munching on popcorn.

She lets Ortiz carry on because it gives him dignity.

Equal justice under the law

Two troubled and recent executions in Arizona and Oklahoma, Prejean hopes, will trigger more opposition to carrying out the death penalty in the United States, the only country in the Western hemisphere that still puts the convicted to death.

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A 2013 Gallup Poll found that 60% of Americans still support capital punishment, though that number is the lowest it has been since 1972, when the Supreme Court constitutionally banned it.

Executions are shrouded in secrecy, masked, sanitized, Prejean says. She remains convinced that if people could see the brutality of killing a human being, they might reconsider their support for the death penalty.

Execution is torture, she believes. And so is the time waiting for it. Death row inmates, she says, "die a thousand times before they physically die."

The July 23 execution by injection of Joseph Wood in Arizona took nearly two hours. Witnesses reported that Wood snorted and gasped for air throughout the process. The April 29 execution of Clayton Lockett in Oklahoma turned into a grisly show as he convulsed and writhed on the gurney and finally died of a heart attack.

Both men committed chilling crimes. Wood shot his former partner, Debbie Dietz, and her father, Gene, at their body shop in Tucson. Lockett shot 19-year-old Stephanie Neiman and then watched accomplices bury her alive.

Early Wednesday morning, Missouri became the first state to carry out an execution since the "botched" lethal injections. The state put to death Michael Worthington for the 1995 rape and murder of college student Melinda Griffin.

Death penalty supporters accuse Prejean of having empathy for undeserving, coldblooded killers. The crimes justify the punishment, they say.

But even advocates of capital punishment, like R. Albert Mohler Jr., president of the Southern Baptist Theological Seminary, have said it's one thing to support death as punishment and quite another to explain it, fix it and sustain it with justice.

Prejean wants Americans to understand that it's not just the act of killing that was botched in the cases of Wood and Lockett. She believes the entire death penalty system is botched -- from the moment an arrest takes place to the trial, conviction, appeals and execution.

"It is random, arbitrary and capricious and disproportionately meted out to minorities and poor people," she says. "Race plays such a huge role."

If you kill a person of color, Prejean says, you are not likely to be condemned.

In 76% of cases in which death is the punishment, the victims were white, according to the Death Penalty Information Center . Almost 42% of death row inmates are black even though African-Americans make up about 12% of the U.S. population.

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She directs much of her wrath at the Supreme Court, which, she says, has given absolute power to the states without demanding transparency. Trying out new drug cocktails for lethal injections, she says, amounts to medical experimentation on human beings to see what it takes to kill a person.

The ruling found that in the most heinous crimes, the death penalty could be employed; it laid out certain procedures to prevent prejudice and arbitrariness in state trials.

But Prejean asks: How can 50 states, bound by the same Constitution and Supreme Court rulings, behave so differently? The high court's guidelines, she says, are unclear and not workable and so what happens is the culture of each state takes over.

There's a reason, she says, that a good number of death row inmates are in Southern states that supported slavery.

A soul on fire

For a Catholic girl in the 1950s, reaching adulthood meant two things, Prejean jokes. It was either time to get married or enter the sisterhood. She chose the latter and joined the Sisters of St. Joseph of Medaille, now known as the Congregation of St. Joseph.

She had been raised in a comfortable household in Baton Rouge, Louisiana, blind to the brutality of Jim Crow laws, oblivious to American poverty.

But in the early 1980s, she had an awakening of sorts and decided to dedicate her life to the poor. She went to live at the St. Thomas housing project in New Orleans, a white nun sharing space with very poor black people. That was the start of her real education.

Prejean began exchanging letters with death row inmate Patrick Sonnier in 1982. His execution was the first she witnessed.

It was while living there that she began communicating with Elmo Patrick Sonnier, prisoner number 95821 at Angola.

Sonnier and his brother Eddie were convicted in 1978 of abducting a young couple, Loretta Bourque, 18, and David LeBlanc, 16. They raped her and then forced both of them to lie face down on the ground and shot them.

Sonnier told Prejean that he was Catholic and asked her to become his spiritual adviser. It was one thing to write letters, she thought. It was another to visit death row.

She was scared to walk into the belly of the beast. She'd never faced a murderer before. The warden asked her what a nun was doing there. She told him she'd come to help Sonnier take responsibility for his terrible deeds.

She wondered if he would be a monster.

But everything changed when she saw Sonnier's face. She knew then that whatever unspeakable act he had committed, his life was worth more than what it was in that criminal moment.

She visited him at Angola until the day he was put to death, April 5, 1984. It was the first time in her life that she had stood up for something.

When he was strapped into the oak electric chair, nicknamed Gruesome Gertie, Sonnier looked at Leblanc's father and asked for forgiveness. And before almost 2,000 volts charged through his body, he found Prejean's face on the other side of the glass window.

"I want the last thing in this world you see to be the face of love," she'd told him. "You look at me."

Sonnier's eyes met Prejean's. "I love you," he told her.

She stretched her arm toward him. "I love you, too."

When it was over, Prejean felt a cold descend on her. On the trip back from Angola, she had to stop the car to get out and vomit.

She would never be the same again. The state's execution of Sonnier set her soul on fire.

'Dead Man Walking'

Prejean has witnessed five other executions since that day. She's written two books: "Dead Man Walking" was turned into a movie starring Susan Sarandon and Sean Penn; "The Death of Innocents" focuses on two men she believes were wrongly executed. She is working on a third book now, a spiritual memoir called "River of Fire."

"Dead Man Walking" sparked a national debate on the death penalty at a time when executions were more common than they are now. Since 1976, America has put to death 1,385 people.

She travels around the world, lecturing on capital punishment -- she savors airplanes as her cloister, where no one can get to her. She often attends performances of the play "Dead Man Walking," written by Tim Robbins for student actors and audiences. It is intended to make a new generation of Americans ponder the death penalty.

All of it has contributed to making Prejean one of America's best-known anti-death penalty activists. She has been nominated for the Nobel Peace Prize three times.

In her hectic life, she still finds time to meditate every day and attend weekly Mass at St. Gabriel the Archangel, a predominantly African-American Catholic Church in New Orleans.

After all these years, her body tires more quickly but the fire inside still burns.

I'd read Prejean's books, seen "Dead Man Walking" several times. I had an image in my mind based on Sarandon's portrayal of her. Compassionate, committed, dedicated, serious about her work.

I wondered if I would find a woman who had grown weary from 30 years of death. I discover otherwise.

She repeats a joke she told recently at a California forum celebrating the life of Catholic priest and Earth scholar Thomas Berry.

"There's an old guy sitting on a bench with a young guy with a Mohawk hairdo and covered with tattoos and piercings," she begins in her deep Cajun voice.

"Whassa matter, pops? Didn't you ever do something wild in your life?" asks the young guy.

"Yeah. One time, I had sex with a parrot. I was checking you out and thought you might be my son."

Prejean looks at me with a mischievous smile, taking in my shock at a nun -- a death penalty nun -- making a rather juvenile joke.

But without humor, without relaxation and good friends, her work would be overwhelming.

She dispels every cliché about Catholic nuns. She's wearing a blue printed blouse, cotton pants and tan leather mules. She doesn't even have a cross around her neck.

I ask about her lack of gray hair, despite the stress in her life.

"I don't know how that happened. It's like the immaculate conception." Then she admits she likes to keep it that way so it matches her spirit.

Prejean with actress Susan Sarandon, who won an Oscar for her portrayal of the nun, and Father Roy Bourgeois at protest in Fort Benning.

Sarandon was equally surprised by Prejean's demeanor when she first met her. "Dead Man Walking" had just been published. The Hollywood star was in New Orleans filming "The Client" and called up Prejean.

They met for a crawfish dinner at The Bon Ton Café on Magazine Street.

"I have to say I was predisposed against religion," Sarandon says of her Catholic school experiences. "I brought all that baggage to dinner. But she was very accessible. She has a bit of wonder."

Sarandon was taken with Prejean's personal involvement with death row inmates; that she never asked about their guilt. She had the unconditional love of a mother for her child.

"I became completely mesmerized," Sarandon says. "She was a big laugher, eater, drinker. We ate tons of crawfish that night.

"People have such a wrong idea of activists. They think of these people as scolding, guilt-making personalities when it has been my experience that they are the most celebratory -- dancing, singing, partaking of food and wine in the biggest way possible. Craving for social justice is another craving they have and that doesn't mean they are closed off to other avenues."

Sarandon made no promises to Prejean that night but told her she was interested in making a movie. It took nine months before she could convince her then-partner, actor/director Robbins, to read it and take on the project.

In 1995, the movie, co-produced and directed by Robbins, screened in American theaters. Sarandon won an Oscar for her portrayal of Prejean. Sean Penn's character, Matthew Poncelet, was a composite of Patrick Sonnier and Robert Lee Willie, whose crime sounded like it was straight out of Truman Capote's "In Cold Blood."

A grave mistake

When a death penalty lawyer contacted Prejean and filled her in on Willie's crime, the first people she thought about were the victim's family.

Faith Hathaway's stepfather and mother, Vernon and Elizabeth Harvey, had both been very public with their support for the death penalty. They said they couldn't wait to see Willie fry.

Prejean had never visited the families of Sonnier's victims. The first time she saw them was at a clemency board hearing where she asked the state to spare the life of the man who killed their loved ones.

The family of Loretta Bourque, one of Sonnier's victims, later told reporters that they were deeply hurt that Loretta's death was used to sell an anti-death penalty book and movie without anyone ever speaking to them.

Prejean recognized she'd made a grave mistake -- one she was determined not to repeat -- even if the families rejected her. The church, she says, has to be on both sides.

She knew many victims' families despised her, as did advocates of the death penalty. They saw her as someone who showed sympathy for vile human beings who deserved to die for their sins. They blamed her for not siding with innocent victims. There were some crimes, they argued, that just could not be forgiven.

Willie's was one of them.

He and his accomplice, Joseph Vaccaro, blindfolded and raped 18-year-old Hathaway, then stabbed her in the neck and upper chest 17 times. They left her to die in the woods. Some fingers of her right hand were missing; she'd tried to shield herself from her attackers.

Four years after the murder, when Willie's execution seemed imminent, Prejean went to visit the Harveys at their home in Covington, a small town on the north side of Lake Pontchartrain. She thought of a prayer to Mary, who watched her son dying on a cross. "Great as the sea is thy sorrow."

The Harveys talked about their daughter and the events of May 28, 1980, the day tragedy struck their family. They talked about what Willie and Vaccaro had done to their daughter in graphic detail.

They told Prejean that the only way to be certain an unrepentant madman like Willie would never kill again was to kill him. Prejean recounted her conversation with the Harveys in her book.

"The SOB, Vaccaro, got a life sentence," Vernon Harvey told Prejean. "And it's been four years and they haven't fried Willie's ass yet. We've been waiting and waiting for justice to be done. All you hear about these days is the rights of the criminal. What about our rights? Don't we have a right to see this chapter closed?"

The intensity of the Harveys' sorrow silenced Prejean in that moment.

But now, 30 years later in her modest New Orleans Mid-City apartment, she explains why she believes the death penalty re-victimizes people.

If a killer is sentenced to life in prison, he or she is locked up and never heard from again. But a condemned man?

That killer makes news every time there is movement in the case: a hearing, an appeal, a court ruling. Death row inmates typically spend over a decade awaiting execution, according to the Death Penalty Information Center. Sometimes, it can last over two decades, as was the case with Troy Davis, put to death in Georgia in September 2011 for the killing of a police officer in 1989.

Prejean says she has seen victims' families follow cases through the courts for years. They wait and wait, reliving the crime over and over again with the hope that they will find "closure" when the killer dies. The Harveys, Prejean says, could have watched Willie get electrocuted a thousand times and still it would never fill the void in their lives.

Vernon Harvey, she says, was a thirsty man drinking a tall glass of salty water.

"He went home after they killed Willie but (his daughter) Faith is never going to sit in her chair again," she says. "Victims' families buy into the notion that the death penalty is a way of honoring their loved ones."

A growing number of victims' families are speaking out against capital punishment, she says. In 2007, 62 families sent letters to New Jersey legislators urging passage of an abolition bill. They emphasized the painful toll the process had taken on them.

Prejean has a framed photo of a brightly lit Colosseum, home to gladiators and executions during the Roman Empire. But in the 1990s, Rome began lighting up the ancient arena every time the death penalty was abolished somewhere in the world. It did just that the day New Jersey's bill became law.

'Nunzilla,' and ardent foes

Prejean's apartment is filled with art, books and photographs. There's a depiction of Christ done in batik, which she acquired in Jaipur, India. She calls it her "yogi Jesus." And a Bible verse, John 10:10, written in Korean calligraphy.

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I ask her what it says. "I ain't a Baptist so I don't know Bible quoting like a Baptist," she says, picking up her holy book to look up the verse.

" 'I have come that they may have life to the full.' "

On her coffee table is a magazine with Sarandon on the cover. And a copy of J.D. Salinger's "Franny and Zooey." She likes the image of the Fat Lady in that book. Jesus, she says, was the Fat Lady, representing people with faults whom no one loves.

Next to the table, on a buffet, is a photo of Prejean's mother, from whom she says she gets her spunk, and a toy that Sean Penn sent to her. It's a windup plastic nun that sparks fire from her mouth.

"I told him: 'Sean, Nunzilla's gonna get you.'"

Next door is the office for Prejean's Ministry Against the Death Penalty . Her longtime friend Sister Margaret Maggio runs the place and makes sure Prejean is on track with her hectic schedule.

"Helen thinks big. She has big dreams, big hopes," Maggio says. "I'm detail-centered. I'm the backbone."

Maggio keeps track of all the letters and e-mails Prejean receives. They are kept neatly in folders. One, colored purple, is called "Ardent Foes." In it are printed copies of e-mails lashing Prejean.

One man wrote: "There has not been one instance on the planet where an executed convict ever committed another homicide. The U.S. justice system is the fairest in the world. If you are judged guilty by a jury of your peers based on the evidence presented that is the way it works. If you do not like it then get out of the country."

Prejean marked it a "classic" and asked her staff to post it on her Web page.

In the days ahead, she will travel to a monastery in Wyoming to complete her memoir. Then she will return home to Louisiana to visit Manuel Ortiz on death row again.

She holds on to an idea that was cemented the moment she threw up after Patrick Sonnier's execution: that Americans are far removed from state-sanctioned death but when they get close to it, they will reject it.

"And I see that happening," she says, the smile wiped off her face.

Her wish is to see the death penalty abolished in her lifetime.

For a second, I think Prejean will break the seriousness of the moment with another one of her "bad Cajun jokes," as she calls them. Instead, she asks: "You hungry?"

It's time to go grab a Louisiana Po' Boy.