Death row defender

In 2002, eight years after the original trial, Stafford Smith secured a retrial for Langley. But this time he had an unlikely champion: Lorilei Guillory, the mother of the murdered boy. After meeting her son's killer she became convinced that he was mentally ill and did not deserve to die. Her moving defence was instrumental in getting his death sentence revoked.

Guillory's extraordinary story is told in a play running at the Pleasance during the Fringe. Australian company Theatre Tarquin used transcripts of Guillory's own words to recreate her story. Stafford Smith, who helped the company with their research, says: "Lorilei is one of my heroes, she's absolutely fantastic. Stereotypically she would be written off as a red-neck Southern alcoholic, but she was able to show more compassion than almost anyone else I've ever seen."

Six-year-old Jeremy Guillory was murdered in 1992 by Langley, a known paedophile. Langley confessed to the crime, but Stafford Smith quickly realised he was mentally ill and entered a defence of insanity. Unfortunately, this was not accepted by the judge and jury who found him guilty of first degree murder.

"He was convicted on my birthday in 1994, I'll never forget that, and sentenced to death three days later. It was probably the worst moment in my whole career. I've lost six clients to the gas chamber or the electric chair, and that's horrible, but in a way, losing a trial is worse. When you do a trial you've got an opportunity to have 12 people make an open decision, and when those 12 people decide that someone who you've inevitably become close to deserves to die, there's nothing more crushing. It was totally my failure and my responsibility that put Ricky on death row."

Stafford Smith continued to fight for Langley, but he had not counted on the help of Guillory, the mother of the boy he killed. "After the death of her child, Lorilei had plumbed the depths of depression and alcoholism. The prosecution had held out the false promise that executing Ricky Langley was going to be a catharsis, a salve for her wounds, and gradually she came to recognise that was a lie.

"In the end Lorilei decided of her own accord that she wanted to meet Ricky. It's one of those things that in classic legal training you're warned not to do, but that's rubbish, you can't exalt legal nonsense over humanity. We arranged for her to spend as long as she wanted with Ricky. She spent three hours with him. At the end of their conversation she said: 'Ricky, I'm going to fight for you.' "

Stafford Smith emphasises that Guillory does not forgive her son's killer, but she came to realise through hearing his own story of abuse, neglect and schizophrenia, that there were reasons - though not excuses - for his actions. She became convinced, as Stafford Smith is, that Langley was insane at the time of the killing.

Langley's problems began before he was even conceived, when his parents were involved in a horrific car crash which killed their five-year-old son Oscar Lee and left his mother seriously injured. Somehow, while being treated for her injuries, she became pregnant, but the pregnancy went undetected for five months. "Meanwhile," says Stafford Smith, "doctors were administering this incredibly powerful cocktail of narcotic drugs to her. And inside her was Ricky Langley, in a womb-bath of drugs, his own little private Hiroshima."

When the pregnancy was discovered, Ricky's mother wanted to take doctors' advice and have an abortion, but her husband refused to allow it. Into these circumstances, Ricky Langley was born. He was sexually abused in childhood, and developed an obsession with his dead brother, Oscar Lee, whom he believed talked to him.

When he was 19 he was convicted of crimes against children and jailed. "For the first time he got therapy, they taught him that he was a paedophile and that inevitably he would re-offend. And Langley - who's a smart guy despite everything else - recognised this and requested to be locked up for the rest of his life.

"But, the system being what it is, he was released."

Guillory's decision to testify in Langley's defence at his second trial was opposed by her family, and by the prosecution. But she was resolute. She asked Stafford Smith to ask her only question in the witness box: "Do you have an opinion as to whether Ricky Langley was mentally ill at the time that he killed your child?"

"And her response was: 'Yes, as a matter of fact I do. I think that Ricky Langley has been crying out for help since the day he was born, and for whatever reason his family, society, the legal system have never listened to him. I believe he was mentally ill at the time he killed my child. And even though, as I sit in this witness chair, I can hear the death cries of my own child, I also can hear Ricky Langley crying out for help.' My God, it made me cry, it still does!"

Langley's death sentence was revoked, but he still faced life imprisonment without parole. "So then the question became: 'should Langley appeal?' Langley took the position that he was unwilling to put Guillory through that, even though it meant him serving life without parole as a paedophile in a horrible prison. Guillory, on the other hand, took the position that he should appeal, and she was not going to rest until he was in a mental hospital." Stafford Smith expects a further retrial to be granted by the authorities in the next year.

Lorilei is one of a number of plays at the Fringe this year dealing with death penalty issues. The Exonerated, at Assembly at the Queen's Hall, starring Aidan Quinn, is the story of six people sentenced to death but later found not guilty. Its New York run received the support of stars such as Susan Sarandon, Danny Glover, Debra Winger and Steve Buscemi. One Act of Madness (at the Bedlam Theatre) and If You Don't Like It You Don't Have to Watch It (at Greyfriar's Kirk House) also deal with the subject.

Stafford Smith believes that theatre can be important in exposing a wider audience to the issues. "Issues such as the death penalty tend to get monopolised by lawyers, and they get transformed into legal issues instead of human issues. We shouldn't depend on lawyers alone to propagate morality. We need to attract different people into the struggle.

"There's nothing in the world that distills hatred towards a totally powerless person more than the death penalty. And when I see that sort of hatred, I just have this natural desire to get between the people doing the hating and the person who's the subject. It strikes me as a very useful rule to run your life by."

This principle has made this public school-educated Englishman a champion of some of the poorest and most despised people in America. He went to death row first as a journalist, then trained in law at Columbia and became a specialist in death penalty cases.

Stafford Smith is 45 with cropped greying hair, his most distinguishing feature his piercing blue-grey eyes. "I wear glasses," he says, grinning, "so I don't look psychotic. I did a TV thing once where I was trying to make a client look insane, and I succeeded, but my sister said it was a close-run thing!" The legal fraternity might see him as eccentric, he says he's a "pathetic optimist".

He and his wife Emily Bolton, also a lawyer, run the charity Reprieve, which supports prisoners on death row and campaigns against the death penalty worldwide. The couple moved back to the UK a year ago after 26 years - "even on a life sentence you normally get released after 26 years" - though they will continue to work on American cases, such as that of Scot Kenny Richey, who is on death row in Ohio.

Stafford Smith is concerned about the way his homeland is going. "One of the reasons I wanted to come back to Britain is that I desperately wanted to do my part to make sure we don't follow the path that America has chosen.

"The most effective counter-terrorism measure available to us is the rigorous enforcement of human rights. Not to do so is to play into the hands of extremists, and you create dozens more people who abandon the cricket pitch for the suicide bomb."

Recent work has included the release of four Britons from Guantanamo Bay, and he still has many clients there. Stafford Smith is planning another trip to the detention centre, in the full knowledge that he is not a popular guest with the authorities there.

"They are really tightening up around Guantanamo. There is a list of people they see as trouble-makers, and I'm right at the top of it. I hope to make it to Edinburgh to see the play - but that depends if they let me out of Guantanamo!"

Lorilei is at the Pleasance Jackdome until August 29.