Memoirs of a Radical Lawyer

In 1924, the American lawyer, Clarence Darrow, achieved notoriety for his successful defence of the teenage thrill-killers, Nathan Leopold and Richard Loeb. His argument against imposing the death penalty on the basis of insanity secured Darrow's reputation as "the Great Defender". Setting out his motivation in 1902, 22 years before the trial, Darrow stated that "liberty is the most jealous and exacting mistress that can beguile the brain and soul of man".

The unorthodox career of civil rights barrister Michael Mansfield has undoubtedly been influenced by a similar dedication to the cause of liberty. Both men are characterised by the same spirited fascination with defending the seemingly indefensible, and conducting trials where the press and public have pre-determined the guilt of the accused. Now Mansfield has chosen to put an end to his criminal defence practice after 42 years as a persistent thorn in the side of the Establishment. The publication of his memoirs presents his final closing speech before the court of public opinion. It provides a fascinating insight into the mind of a man who has devoted his life to securing the liberty of others.

Born just two years after the death of Darrow, Mansfield grew up in Finchley, in domestic circumstances which gave little indication of his eventual anti-Establishment stance. An incident in which his mother was wrongly accused of a minor parking offence is credited by Mansfield as the start of a deeply-held distrust of authority. At eighteen he went to study philosophy at Keele under the empiricist Professor Antony Flew, who imbued in Mansfield a sense of both the importance and limitations of scientific method.

Mansfield was called to the Bar in 1967, where, despite his initial training in a prosecution-orientated chambers, he quickly established himself as a passionate and effective defence advocate. In many respects, the purpose of a trial is to freeze a moment in time, in order to conduct a postmortem in the clinical setting of a courtroom. Events can be taken apart and analysed for emotion and motivation. It can then be at least partially reconstructed with the help of eyewitnesses and the tools of forensic science. Mansfield sets out his approach, always focusing on the weakest link in the chain of the prosecution's argument, whether it be forcibly extracted confessions, or unreliable scientific evidence.

These memoirs benefit from a career spent at the heart of some of the most controversial criminal cases of the past four decades, including those of Barry George, the Birmingham Six, the "Ricin" trial and the posthumous appeal of Ruth Ellis, the last woman to be hanged in the UK. Mansfield has also undertaken a large number of high-profile inquiries, from Bloody Sunday to the inquest into the death of Jean Charles de Menezes.

It is in the transcripts of his cross-examinations where the book really comes alive. John Mortimer once recalled his father's advice that "the art of cross-examination is not the art of examining crossly". Similarly, Mansfield's handling of witnesses shows a deftness and lightness of touch, combined with an unrelenting grasp of the underlying details. His style is reminiscent of Darrow's approach during his great cross-examination of the evangelist preacher-turned prosecutor, William Jennings Bryan, during the "Scopes Monkey Trial", which was credited with the premature demise of Bryan shortly after the trial. During the long months of the Bloody Sunday Inquiry, it was Mansfield's patient questioning of "Soldier F" which uncovered his vital admission of having shot the unarmed Barney McGuigan. He became so notorious for his dissection of witnesses, that "being Mansfielded" entered the police lexicon for those who were subjected to the ordeal.

Mansfield has always prided himself on taking a different approach to his involvement in cases. Whilst his fellow barristers stuck to the prevailing orthodoxy of detached involvement with those they represent, Mansfield invests himself personally in each case. Although this imbues his reminiscences with an undeniable emotional intensity, it does lead to the occasional lapse of perspective.

In particular, the re-telling of his work for Mohamed al Fayed during the Diana inquest betrays a streak of paranoia. In an interview with the Guardianin 2003, he said "this cannot be an accident. [T]he dark forces are at work here". Mansfield goes on to reveal in the book that "I found it difficult simply to accept that what happened in the Alma Tunnel in Para was 'just one of those tragic things'. Of course it might well have been, but that's what 'they' always hope we will think". At the outcome of the inquest, the coroner Lord Justice Scott Baker, noted acidly that parts of Fayed's case had been "demonstrably without foundation".

Despite these difficulties, Memoirs of a Radical Lawyer is, on the whole, tightly written, and, despite its length, manages to distil his cases down to their central issues with a minimum of jargon, making it an enjoyable read. At the climax of his first defence speech in 80 BC, Cicero questioned the public interest surrounding the trial: "Perhaps it is the fact that my client is being properly defended that makes you feel so outraged." No doubt the outrage generated by Mansfield's career is, in no small part, due to his ability to ensure that even the most reviled defendant has access to the level playing field so fundamental to the justice system.

Thom Dyke is a pupil barrister at Hardwicke Building