By Dan Bell BBC News, London

Sarah Smith is ready for the gruelling work

Sarah Smith, 25, from Barking, east London, is one of about 20 British lawyers each year sent by a London-based charity called Amicus to assist death penalty defence attorneys in the United States.

The charity provides legal training, arranges placements with defence lawyers and reaches out to law schools across the UK.

Amicus was set up after the execution of Andrew Lee Jones in Louisiana in 1991.

Opponents of the death penalty say Mr Jones's case highlights problems with the system.

His court appointed lawyer had never before represented someone facing the death penalty.

It's mostly poor people and damaged people who are receiving the death penalty, and not the worst of the worst Robin Maher

He only received papers for the case shortly before the trial, and he saw Mr Jones only a handful of times. The lawyer later apologised for not giving Mr Jones a fair defence.

"One of the major problems is the dearth of adequately qualified and compensated defence counsel," said Robin Maher, Director of the American Bar Association Death Penalty Representation Project, and an Amicus adviser.

"It's mostly poor people and damaged people who are receiving the death penalty, and not the worst of the worst," she added.

Ms Smith recently graduated with a Master's Degree in law at University College London, and plans to go into criminal practice when she returns.

Low IQs

She was determined to do something worthwhile before beginning her career, "rather than doing something in the City that I wasn't too invested in and was just about the money," she says.

After a friend returned from an internship in Louisiana, she knew it was something she had to do.

"It's an opportunity I can't turn down," she says. "What everybody has to agree with is there has to be sufficient resources to provide a solid defence."

There are just under 3,400 people on Death Row in the 38 states that practise capital punishment. In the past 12 years, at least 30 people have been executed who had IQs below 80.

Carlos Cuesta is on Death Row

There is also a risk of executing an innocent person. Over the last 33 years, 123 people have been exonerated and released after being sentenced to death.

Ms Smith is due to work on the case of Carlos Cuesta, who is accused of killing his girlfriend in front of her pregnant daughter.

She will interview witnesses, aid in jury selection, serve subpoenas, give advice on which evidence to present, and she will go into prison and get to know Mr Cuesta as he awaits trial.

"It will be an excellent opportunity to get to know ... the practicality of dealing with defendants," she says.

"I don't think my opinion is any more valid than anyone else's, it isn't why I'm going to death row," she says. "It really is about fair trial issues."