Ruth Ellis and James Hanratty are long dead but their anguished families have challenged the basis on which they were both convicted.

Lucy Hickman talks to lawyers about seeking justice from the grave

Clients can be the bane of a criminal lawyer's life.

Saying the wrong things to the wrong people at the wrong time and, of course, they 'never did it'.

But there is something more challenging than a living client - a dead one.

Especially one who has been dead for 50 years or so.

The latest prominent reopened case of this ilk to hit the courts and the headlines was that of Ruth Ellis, who, in 1955, was the last woman to be hanged in Britain.

Her family's solicitor, Cardiff-based Bernard de Maid, sought a manslaughter verdict on the grounds of provocation, claiming the nightclub hostess, who shot her lover David Blakely at a London pub, suffered 'battered woman syndrome'.

But the three Court of Appeal judges upheld the murder conviction last month, claiming the appeal was 'without merit'.

Lord Justice Kay criticised the Criminal Cases Review Commission (CCRC) - the watchdog body that reports on possible miscarriages of justice, for referring the case.

Mr de Maid had more success in 1999, when he helped clear the name of a Somali seaman hanged in 1952 in Cardiff for murder.

Last June, Liverpool solicitor Robin Makin acted in a reference to the Court of Appeal, which overturned the conviction of Liverpool labourer George Kelly, who was executed following his trial in 1949 for the infamous 'Cameo Cinema' murders.

In 2001, a researcher came across a witness statement that accused another man of the murders but had not been disclosed to the defence.

It was thought possible that Mr Kelly might have been acquitted had it been disclosed, and the conviction was overturned.

Tamsin Allen, who specialises in miscarriages of justice at London firm Bindman & Partners, acted for the families in the high-profile cases of Derek Bentley and James Hanratty.

Mr Bentley was hanged in January 1953 for his part in a robbery on a Croydon warehouse during which his accomplice, Christopher Craig, shot and killed a policeman.

Despite conflicting evidence over whether 19-year-old Mr Bentley knew Craig was carrying a gun, and debate over Mr Bentley's ambiguous words, 'Let him have it', the jury convicted him of murder.

Craig, then being only 16, was spared execution.

Hanratty was hanged in April 1962, after being convicted of shooting dead Michael Gregsten, and raping, shooting and leaving for dead 22-year-old Valerie Storie.

Ms Allen was given the Bentley file when a trainee at London firm BM Birnberg (now Birnberg Peirce & Partners).

'I was handed a lot of dusty old boxes and asked to do something with them.' She joined Bindman & Partners specifically to take on the Hanratty case.

The attempt to clear Hanratty failed in 2001 after the Court of Appeal decided that DNA evidence established his guilt 'beyond doubt'.

However, Mr Bentley was posthumously cleared, and Ms Allen says his family 'have been well compensated on an ex gratia basis'.

Ms Allen says that working on the cases was 'fantastically interesting'.

She continues: 'What I loved most was the research.

It was amazing unfolding a story from these dusty, old boxes.

I was always finding something stunning that had never appeared before.

'I spoke to Michael Sherrard, who was junior counsel on the Hanratty case and was extremely useful in seeing if things were disclosed.

He would say things like "if only I had known that, I would have used that in argument".'

She says she revisited the crime scenes and took measurements and timings to compare with the original evidence.

She also re-interviewed surviving witnesses who had varying strength of memory.

'Chris Craig had exceptional recall.

The police claimed he had said and done things he hadn't.

He remembers exactly what Bentley said and did on the roof.

The whole crux of the case was that Bentley intended a violent act but Chris is certain he never showed the gun to Bentley because he knew Bentley was a big softy.'

Before Ms Allen could access all the documents on Bentley, she had to apply for the lifting of the 50-year retention of secrecy on the state documents that the government had slapped on the Bentley file.

'It takes a lot of time and pressure to get a government organisation to be open, particularly when it's to do with policing.

But by the time I came to do Hanratty, there was an interesting change of attitude by the police and Home Office, and documents were more easily available.

'One of the challenging things about these cases was evidential.

It was surprising what was retained though.

The police kept everything - even documents that had not been disclosed.

In the Hanratty case, there were 2,000 undisclosed documents - I had to go through them all.'

Ms Allen says she was lucky with both sets of families, which ran organised campaigns and had unearthed masses of information.

'It might have been difficult working with the families because they are very emotionally involved, but both the surviving members of the Hanratty and Bentley families were fantastically helpful and easy to deal with.

'The Hanratty family was upset at the attitude of the Court of Appeal, but Hanratty's brother, Mick, said it had been worth it because at least now he understood how the conviction was obtained and what went wrong.'

She says another challenging aspect of the cases was conducting them in the public eye.

'People have grown up with these cases and they are considered public property.

It is very satisfying doing something that matters to people but you spend a lot of time dealing with these people.

I had one person in Hanratty who wrote to me practically every day.

Sometimes it can be useful but it can be quite challenging.'

Ms Allen does not think the judge in the Ellis case was entirely fair to blame the CCRC.

She says: 'The cases are expensive and no one is waiting in jail for release; the CCRC gets criticised.

But it is incredibly important for the families to establish what really happened and important for the reputation of British criminal justice.

People have felt for years that something was wrong in these cases.

They need to have their minds put at rest.

'Both times I dealt with the CCRC, they were great.

My experience was unusual because both of my cases were extremely high profile so I got the top dogs round the table, but I found them extremely interested, sensible and efficient.'

Tony Foster, a CCRC member since the body's formation in 1997, says that although applications in old cases arrive in the same way as any other, the CCRC has to exercise more imagination in investigating them.

'We have all sorts of possible sources, and we have to use our imagination and our investigative techniques to the full to find things out.

'The transcripts of the summing up are not kept indefinitely, although some of the most famous cases are preserved and might be kept in the Supreme Court Library or the Public Records Office.

We will look at anything which might give an indication of what happened, for example the notebooks of the judge or the clerk.

'Things turn up in surprising places.

It can be a bit hit and miss, and key pages of documents can be missing.

But you don't expect tidy files or everything in one place.'

He explains that a key requirement that will prompt the CCRC to consider a referral is new evidence or argument not available at the original trial or appeal.

'It is a rigorous intellectual activity sorting out what is being said and how it is different to before.

It may be a new witness or a witness saying something different.

It could be a new legal argument or a case which should be referred because the state has changed the concept of fairness and the directions from the judge to the jury on the law would have been different.'

The CCRC receives around 950 applications every year, with about 4% of these being referred to the Court of Appeal.

'Of these, about two-thirds had their convictions quashed or their sentences amended.

We wouldn't expect 100% but I don't think we have put forward hopeless cases,' he says.

Noam Almaz - a trainee solicitor with London firm Hickman & Rose - acts for a Hungarian national who has spent the past 38 years in prison and mental institutions for the murder of an employment agent who refused to consider him for jobs.

Mr Almaz is fighting to clear his client of murder on the grounds of provocation and diminished responsibility.

He is amazed at how the papers show how things have changed.

'It is a very different London that comes out from the papers.

It brings to light a small area of the 1960s.

Some of the statements are handwritten in great flowery script which is barely readable.

'There's also a huge difference in the amount and types of evidence.

There are only about 100 pages for the whole trial and there are no medical records.

The psychiatrist's report is just two pages long and effectively just says "he's sane".

'If it was tried again today, you would get an expert's report from the defence, and a different one from the Crown.

But a lot of the evidence was brushed under the carpet.

My client felt the whole system was racist and he wouldn't get a fair trial because he had killed an Englishman.'

Mr Almaz dug out much of the old evidence from the Court Service.

'It was a very odd department which I have never had to deal with before or since.

There was no activity there at all and no phones rang.

I went through about ten departments trying to locate someone who knew something about it.'

When it comes to digging up history, however, few can surely match the efforts of the family of Dr Samuel Mudd, the man who - a mere 138 years ago - treated President Abraham Lincoln's assassin, John Wilkes Booth, following his escape from Ford's Theatre in Washington.

He was convicted of aiding and abetting as an accessory after the fact in the conspiracy to kill Lincoln and other officials, and sentenced to life imprisonment.

The quest was begun in the 1930s by the late Dr Richard Mudd to have a court exonerate his grandfather on the grounds that the military commission that convicted him lacked jurisdiction and that the trial violated his right to a civilian jury trial.

However, the case came to something of a sad end recently when the US Supreme Court declined to hear the appeal after the family's lawyer missed the deadline for filing a petition.

Thomas Mudd, the doctor's great-grandson and plaintiff in the case, told reporters: 'It's heartbreaking to lose this way.

We never held out great hope that the Supreme Court would do justice for Dr Mudd.

But to not even get the case in front of them, after all this time, that's just really hard to take.'

But at least Dr Mudd, unlike other victims of ancient miscarriages, did not lose his life or, for all that long, his liberty.

He was pardoned by Lincoln's successor, Andrew Johnson, because of his work during a yellow fever epidemic while in prison.

Lucy Hickman is a freelance journalist