The police had just found the body of three-year-old Rosie Palmer and picked up a man in connection with her murder. A young pregnant woman - the 12th person Frederick West is accused of killing - smiled brightly from a blurred newspaper picture. The taxi driver, hearing who his passenger was, let rip: 'The guys who do that sort of thing should be strung up. They don't deserve to live. We've got to get tough and show we won't tolerate this kind of thing.'

'I understood why he felt like that,' recounts his passenger, Sister Helen Prejean, a 55-year-old Roman Catholic nun, who has sat in on the executions of three death row prisoners in Louisiana State Penitentiary. 'When these things happen there is such anguish, such a desire for some focus for all those feelings and in England, just as in America, a great many people see the death penalty as the ultimate justice. I wasn't going to change his mind with my words.'

Instead, she would like the taxi driver to see and understand what 'premeditated and sanctioned state killing' really means.

In fact she would like us all to see and understand: she is right behind the move in the States to televise executions and she would have 'this secret ritual which people support as a theory without knowing what the reality means' beamed out at prime time.

We should do as she has and sit with a condemned man (almost all death row prisoners who die are men) in his last hours before he is taken to the electric chair, watch the bizarre ritual of him eating a carefully prepared last meal, see him glance at his watch to note the last minutes of life ticking away, see his hair and eyebrows shaved so they will not catch fire when the electrodes fitted to the scalp are charged. We should hear the wardens arrive, take the prisoner by the arms and announce: 'It's time to go.' We should watch the man being tied into the wooden chair, a strap clamped round his jaw to prevent him screaming, a hood put over his head so the desperate terror and pain on his face as the switch is swung and the electricity charges through his body is never actually witnessed.

'And when it is over we should ask ourselves whether that feels better, whether watching the state imitating the violence that the prisoner meted out to his victims is the best protection and resolution for society that we can manage,' says Sister Prejean fixing me with a challenging, I-have-God-on-my-side look. And, no, she doesn't believe that in societies which turn the most sadistic, macabre and brutal events into popular entertainment, people will just put their feet up with a tub of popcorn and be titillated rather than appalled by what they see. 'It is so cruel, so terrifying and so far from being glamorous that I believe most people would be appalled to realise this is what we sanction through our taxes. I believe it would have the death penalty abolished.'

Sister Prejean was in Britain this week, attending a conference in Glasgow to discuss the death penalty with British law students who are going to work in legal centres in America. She is also here to publicise the book about her experiences which is a bestseller in America, has been nominated for the Pulitzer Prize and is to be filmed with Susan Sarandon as Sister Prejean. The book is an extraordinary, compelling account of the nun's involvement with death row prisoners, but it also deals with those who carry out the death sentence and the victims' relatives, many of whom after their initial fury at her involvement with their loved one's killer, were glad of her compassion.

Sister Prejean is a well-built woman of remarkable stamina and effervescent friendliness. Her manner is intimate, girlish even, and it is not difficult to imagine how, in her night-long vigils with prisoners, even the most seemingly remorseless might accept her friendship and allow her to see his tears.

Not surprisingly she has been accused of the kind of liberalism only indulged in by those who have not lost a loved one to a savage act of violence, and of course there have been attacks of what she describes as the sex-starved-nun-gets-romantically-involved-with-death-row-inmate kind. But Sister Prejean is used to parrying such talk and does not flinch at the suggestion that there may be an element of morbid fascination in her 'privileged' position of spiritual adviser, in being admitted to the execution room: 'I vomited after the first time and had nightmares for weeks. I would have done a great deal not to go in the second time but the prisoner had no one else and is it really right to be put to death without a single person there who cares?'

Compassion there may be but she believes that there are crimes which justify locking perpetrators up for life. And her fight against the death penalty is practical and economic as well as moral: 'Each capital case costs approximately dollars 2.3m - vastly more than imprisoning someone for life and we now have 3,000 people on death row. In New York where they don't have capital punishment and instead spent resources on increasing police on the streets, violent crime was reduced. It does not act

as a deterrent but murders have dropped in states when it has been abolished.'

Her other argument is that the death penalty is discriminatory: it is almost always the poor - 90 per cent had no job at the time of the crime - who end up there; and the vast majority are black. 'If a black kills a white he is very likely to get death. Reverse that and more often than not you find the police won't even try to find the killer.'

So what about OJ Simpson? What happens if he is found guilty of murdering his white wife and friend in a savage attack which, if the tapes now being heard on American television are correct, followed years of wife battering? Sister Prejean laughs and her southern drawl loses its softness: 'If he was any old black guilty of slitting a white woman's throat there would be no hope for him. But what do we see? There's all that support for him, people begging for him to be set free. He's a hero and America can bend its rules for heroes. I would be very surprised, whatever the verdict, if he gets the death penalty.'

And then he can afford to spend dollars 20,000 a day on his defence while most death row prisoners get attorneys from the state who 'don't bother to challenge anything. You can see an innocent man going to his death because nobody cares. There is absolutely nothing democratic about the 'justice' meted out through the death penalty'.

Executions are held up as resolution, a way society shows care for its victims. 'In fact, they divert attention away from the needs of victims while the press records the prisoner's attempts to get a reprieve, all the details of his execution, the feelings of his family,' Sister Prejean says. 'The victim's families also live in a state of suspended animation; waiting sometimes years for the person to be killed, they cannot begin to get on with living more normally. But so often when the execution has taken place, and they have had the 'satisfaction' of seeing the prisoner executed, they find it doesn't help.'

But does this concern us in Britain? We don't have the death penalty and every parliamentary vote since its abolition has been resoundingly against reinstatement. Sister Prejean adjusts the large silver crucifix on her ample bosom and suggests: 'Economic conditions in Britain, a lot of youngsters on the streets with no jobs, feeling disenfranchised, growing violence and a public that wants to feel something is being done: these are all the conditions which we have seen and which have led states to adopt the death penalty.'

It is understandable that anyone who has been through the horror of having someone murdered might want revenge and retribution, but the death penalty does not undo what has happened, nor does it stop it happening again.

Sister Prejean's taxi driver may not see a quick-fix solution in attempting to prevent violent crime by dealing with the kind of childhood deprivation and neglect that offenders such as Robert Black or the boys who killed James Bulger endured. But it is an approach that has not been given the sort of funding our ever-growing prison population and America's penal system have.

Sister Prejean's book, 'Dead Man Walking - An Experience of Death Row' is published by Fount, pounds 7.99.

(Photograph omitted)