Lawyers from White & Case's City office work to clear a man's name in a 30-year-old murder case. Chris Johnson reports

In January 2011, White & Case's London litigation head John Reynolds was perusing the weekend newspapers at his north London home. An avid reader of crime and detective novels, Reynolds was intrigued by an article in The Observer about the Innocence Project, a non-profit group dedicated to exonerating wrongfully convicted criminals through investigation and forensic testing.

The organisation, which was established by criminal defence lawyers Barry Scheck and Peter Neufeld in the US in 1992, had already helped more than 260 individuals get their convictions overturned. One of its cases had been turned into a feature film, Conviction, starring Hilary Swank and Sam Rockwell.

At the time, White & Case's London office was on the hunt for a weighty new pro bono assignment. Taking on an assignment for the Innocence Project – which established a UK arm, Innocence Network UK, in 2004 – seemed like the perfect fit.

Innocence Network had never worked with a law firm in the UK – previously, the casework was entirely handled by university students – while White & Case's London arm had not handled casework relating to a criminal conviction. (In the US, the firm has handled several criminal appeals referred by The Legal Aid Society.)

"We really needed someone to come in with a fresh approach and additional resources," says Innocence Network UK executive director Gabe Tan.

"There's quite a lot of cynicism about corporate social responsibility and pro bono – many law firms seem to just do it to tick a box and get good publicity – but I've already been very impressed by [White & Case's] energy, professionalism and ability to manage things in a more business-like way."

Although Reynolds had been trained as a criminal lawyer and once tried a case at the Old Bailey  – the UK's top criminal court – he admits that it's an area in which the firm has little experience.

"We know we're not criminal lawyers, but that's not what they were looking for," he says. "What they needed was forensic examination and the asking of hard questions, which as litigators is what we do every day."

After some introductory meetings and training sessions designed to teach lawyers from White & Case's London litigation team how to start an investigation and request forensic evidence, the firm was assigned its first case – that of convicted murderer Gary Critchley (pictured). White & Case is working for Innocence in trying to find new evidence to get the recent parolee's conviction overturned.

On a rainy morning in the summer of 1980, Critchley, then 17, was found lying unconscious on a south London pavement with severe head wounds and a broken back, sustained during a fall from an apartment window four floors above. Inside the flat, which was locked from the inside, Edward McNeill had been bludgeoned to death, struck 27 times with a claw hammer.

After spending three months in the hospital recovering from his injuries, Critchley – who also suffered amnesia from the fall and does not remember what happened – was arrested, charged with McNeill's murder and convicted.

Although, as a juvenile, he received an indeterminate term, the judge recommended a maximum of only nine years. By the time White & Case became involved last October, Critchley had already served 30 years.

(Tan says Critchley's maintenance of his innocence led to his imprisonment exceeding the recommended term, since an admission of guilt is a prerequisite for many parole boards. Critchley was briefly released on parole in 2000, but was sent back after a parole violation.)

Despite his assertion that litigators need to be "cold, emotionless bastards", Reynolds admits that the personal similarities between Critchley and himself – both are 49 and share a love of punk rock – meant that his story struck a deep chord.

"We're used to dealing with big corporate clients with billions of dollars at stake, not people's liberty," Reynolds says. "I thought about all the things I had done since I was 18 years old and realised Gary hasn't done any of them.

"He's been stuck in prison with nobody believing him. It's very hard not to become emotionally involved, but our job is not to believe him or to be campaigning for Gary. It's to remain dispassionate and undertake an impartial investigation."

One of the key pieces of forensic evidence that led to Critchley's conviction was imprints in blood at the crime scene that matched a shoe he was wearing when he was found by police. The shoe was two sizes too small for Critchley, however.

It was also a white sneaker – not exactly typical footwear for a punk – and didn't match the leather Dr Martens boot he was wearing on his other foot. And, although the floor and walls of the apartment were covered in blood from the attack – the victim was completely exsanguinated, with no blood left in his body – no traces of that blood were found on Critchley or his clothing.

But obtaining evidence 30 years after a crime is no simple matter. In the UK, defence teams lose the automatic right to disclosure of relevant material at the point of conviction, which for Critchley came with the loss of his appeal in 1983.

White & Case's team of about 18 associates and trainees have submitted freedom of information requests to gain access to such documents as the original police reports.

The already daunting task of finding forensic exhibits, meanwhile, was made more challenging by the recent closure, as a cost-saving measure, of the UK Forensic Science Service – the government body responsible for holding samples of police evidence.

"That was a bit of a setback," deadpans White & Case litigator David Milton, who is leading the firm's day-to-day involvement on the case with fellow associate Rory Hishon.

The ultimate goal is to amass enough fresh evidence to make a submission to the Criminal Cases Review Commission (CCRC) – an independent body that reviews possible miscarriages of justice – on the grounds that the original ruling was, on the balance of probabilities, "unsafe". Critchley's several prior applications to the CCRC, made before White & Case's involvement, all failed.

The film Conviction ends with Rockwell's character having his handcuffs removed and emerging from the courtroom a free man. White & Case will be denied such drama: in March, Critchley was finally released on parole. He is now pursuing a career as a writer and artist – samples of his work can be seen on his website, named after his prisoner number, B39969.org.uk – but the fight to clear his name goes on.

"Gary has been let out of prison, and that is giving him a chance to build a life – I won't say rebuild, as he never had a chance in the first place – but that sense of injustice remains," Reynolds says.

"He won't have closure until he establishes what he wants to establish – that he should never have been there in the first place."

A version of this article first appeared in The American Lawyer, an affiliate title of Legal Week.