The sister of mercy

To the men she tries to save from execution, Helen Prejean is nothing short of a saint. But when Katherine Butler caught up with America's best-known nun in New Orleans, she found an impatient crusader who's only too aware of her human frailties

I am running after a nun. In 80-degree heat, through the backstreets of a Louisiana suburb. She had warned me to lead the way. "Because when I'm talking," she'd said, "I don't know where I am." But I have led her astray. She's not happy, she's galloped off in the opposite direction, leaving me to give chase, feeling as shamed as I did when the nuns at my convent school would quiver with rage over some sinful transgression, like being late for assembly.

Sister Helen Prejean moved beyond the petty restrictions of convent life years ago. As anyone who saw Susan Sarandon's Oscar-winning portrayal of this nun in the 1995 film of her book Dead Man Walking knows, she has her mind on a bigger mission. And being late is not an option.

"It's OK," she forgives me, when I catch up. "I just want to be there for Manuel."

Ten years after the film shocked US audiences, elevating her lonely campaign into nationwide debate, Sister Helen's new book has just been published in the US. This, she hopes, will deliver another miracle: helping to achieve the abolition of the death penalty in America altogether. A book-promotion tour will take her on the chatshow circuit. But, for today, her focus is on the unglamorous reality of death-row justice in a dingy Louisiana courtroom. Manuel Ortiz is a condemned prisoner to whom she has acted as spiritual adviser for five years. Sister Helen is convinced that he is innocent of the murder for which he was convicted. Today he has been granted a hearing that could determine his fate.

I have arrived at 9.30am, on Sister Helen's instructions, outside Jefferson Parish courthouse, across the Mississippi from New Orleans. She wants me to see American justice in action. Sweating para-legals are heaving towers of box-files into the courthouse, and a long line of mostly young men in T-shirts and baseball caps are queuing to be screened for weapons under a large "No Firearms" notice.

I go up to the fourth floor. There's no sign of Sister Helen, but peering through the open door of Judge Jerome Winsberg's courtroom, I see a man seated at a table in a bright-orange prison jumpsuit. His legs are shackled with chains. He looks up expectantly. This is Manuel.

Deliberations are already under way when two women squeeze past the armed officers at the door. Here are the nuns. Sister Helen is dressed in a dark pinafore and cream blouse, a silver crucifix around her neck. Sister Margaret Maggio, who runs her office, follows behind. "You, sir, are a gentleman," Sister Helen whispers loudly to a man who vacates his seat, "but I want Manuel to be able to see me", and heads purposefully for the front row, where she takes a notebook out of her bag.

She needs all the ammunition she can get. This is the deep south, where prosecutors routinely seek the death penalty in murder cases because it goes down well with the public. The climate is such that until a story in the national media about it caused outrage, prosecution attorneys wore ties in court adorned with motifs of a hangman's noose. Most people here accept capital punishment, Sister Helen says, "with the air they breathe and the mosquitoes they swat".

Last night, when I phoned Sister Helen at her New Orleans apartment she was just off a plane from Texas. She travels ceaselessly. But hearing the raucous cajun music from the French quarter outside my hotel, she said brightly: "Sounds like y'all are having some party!". I got the impression that even at 65 she might have been up for a night on the town. At our only previous meeting, she was at a dinner in her honour in an expensive London restaurant. She soaked up attention, drinking champagne and telling stories late into the night.

Now, in court, she leans forward in her chair, listening intently to every word. I have no idea if the man in the orange suit is a murderer. But even to my legally untrained ear the details of his original trial sound far-fetched; the cast of characters might have come straight out of the mind of Elmore Leonard or Quentin Tarantino. The chief prosecutor is now in jail for corruption and bribery. The star witness for the prosecution (a former member of a Honduran death squad) had a string of convictions unknown to the jury at the time.

Every month, Sister Helen drives three hours to the Louisiana State Penitentiary. In a booth separated by a plastic screen, she and Manuel talk about the case, or pray, anything to "give him a little courage" as Sister Margaret says.

Now his attorneys are demanding that the crooked prosecutor be summoned. The state opposes it. The man will take the Fifth Amendment and say nothing. As the procedural impasse continues, the judge takes a call on his mobile phone. My heart sinks on the prisoner's behalf. At the recess, Sister Helen rushes forward to greet the prisoner. "Good to see you Manuel," she beams, showing him a copy of the new book. He raises his manacled wrists and looks apologetic. Death-row prisoners are not allowed to have hardback books.

When Dead Man Walking was being adapted by Tim Robbins for the screen, Sister Helen's order, the Sisters of St Joseph of Medaille, were worried that Hollywood studio bosses would add a cheap love interest or cast the nun as a Whoopi Goldberg type. In many ways such a casting might have been understandable. I can well imagine her scampering over a wall, or taking part in a high-speed car chase if she thought it would help her crusade. It's an image that is reinforced, later, when she tells of how during a visit to the Vatican she once performed a most un-nun like change from trousers into a skirt in an ante room even as the Holy Father was shuffling down the corridor to grant her a private audience.

But, make no mistake, Sister Helen may mix with the great and the good, but her commitment to her cause should never be underestimated. The first time she witnessed a man being put to death in the electric chair she had to stop on the drive home to vomit. After six journeys to the death chamber, she is resigned to living with the nightmares. "They always come in the form of I'm being executed. But I can't afford to let it overcome me because I have to tell the story."

As her latest book, The Death of Innocents, makes clear, she considers all of the six state-sponsored killings she has witnessed to be wrongful, even that of Robert Lee Willie who tortured a woman in a gravel pit for hours before murdering her. Written while she was staying at a Cheyenne reservation in Montana, she returns like a detective to the scenes of the capital crimes of two men she believes were innocent. Her aim is to shock Americans into seeing that the US criminal justice system is so flawed, and the death penalty so randomly applied to the weakest, that it is unconstitutional.

But Sister Helen also takes the reader on the final journey into the death chamber with the condemned men, supplying the kind of detail that is as surreal as it is horrifying. The polished floors, the secretary typing up forms. The guard watching Jerry Springer on television in the corner as the prisoner and the nun have their conversation and a last bowl of chocolate ice-cream. Then the diapers and the strap-down teams arrive before the needles are inserted.

On the way, the book excoriates George Bush and his conservative Catholic ally on the US Supreme Court, Justice Antonino Scalia. Thirty-eight American states still operate the death penalty, of which Texas is the crucible. As governor of Texas, Bush signed more death warrants than any governor in recent history and systematically denied clemency. His habit was never to devote more than 30 minutes to a review. Sister Helen regards his compassionate conservatism as a sham, and thinks people in Britain should be awake to the dangerous parallels between his "war on crime" and his "war on terror", both of which rely on violence and retribution.

"Don't underestimate what is beginning to happen in Britain where you have suspected terrorists," she warns. "British people may say 'we are so beyond this', but you watch what your courts are doing."

The court breaks for lunch and I join the nuns as they rush out to queue at a branch of Subway for tuna wraps and Coca-Cola. Sister Helen talks non-stop the entire way there. Outside on the pavement, it is hot and noisy, but this nun is as practical as she is spiritual; one moment she is quoting the prophet Isaiah in her big, resonant voice, the next she's pushing on the nearest door, which happens to be a bail-bonds office, and asking for a quiet corner in which to sit.

The receptionist looks puzzled at first, but as soon as her boss recognises the nun, we are sitting around the kitchen at the back of the office, eating our sandwiches. Sister Helen, still in full flight about religion, right-wing politics and how America is barely a functioning democracy, pauses only to shout thanks to the bail-bonds man with the unlikely suggestion: "I'll know where to come if I ever need a bail bond".

She tells me how Christianity in America has been hijacked to support a right-wing ideology which fights crime with retribution instead of rehabilitation. "We have so much Christianity-lite in this country, and George Bush is the embodiment of that. People are abysmally ignorant about the Bible and about the gospel of Jesus because all they hear is this stuff they get at the pulpit."

If those she accuses of "manipulating God" are to be found running the government and filling the ranks of America's Christian right, then she is one of the few outspoken voices on the Christian left. She rejects the label, but in her version of Christianity, everyone has an inviolable human dignity. "When you are walking with someone to their death, even when they have done terrible crimes, and they are saying 'sister, please hold on to my life', there is no dignity in this. It is cruel and unnecessary. It involves torture. They are defenceless, and then we kill them."

It is difficult for liberal Europeans to understand the scale of her task in changing attitudes in the red states of America. Conservative websites are filled with references to "frying" convicts and accusing "prissy" campaigners like Sister Helen of "glorifying" murderers. Her answer is uncompromising. "What did Jesus say? 'The least of these.' People considered monsters, throwaways. They deserve full human dignity and the compassion of Christ."

It is on the way back from the bail-bonds office that we lose the way and have to break into a run. Somehow we are back in our seats when a mystery witness takes the stand, an answer perhaps to the nun's prayers. The woman testifies that her husband, the chief witness in the original trial, confessed on his death bed to the murders. It feels like made-for-TV court drama, but there are gasps from the public gallery.

Manuel looks around and searches for Sister Helen's face. She smiles and gives him a thumbs-up. "Poor Manuel," Sister Helen whispers to me, "he knows that this day could decide whether he lives or dies."

She knows that even explosive testimony doesn't always buy you your life back once the door to America's machinery of death has closed behind you.

As I leave her, Sister Helen is speeding off back to New Orleans to meet Sean Penn and Jude Law. They, and Kate Winslet, are in town shooting a new movie. For Sister Helen, the hope must be that life does not imitate art too closely. Sean Penn played the prisoner in the orange suit in Dead Man Walking. And he died strapped to the black padded gurney, his arms outstretched in the shape of a cross.

'The Death of Innocents' by Sister Helen Prejean is published by Random House. Available from Amazon for £12.22