Among the first cases investigated by Leonard Leigh when he joined the Criminal Cases Review Commission (CCRC) were the hanging of Mahmood Hussein Mattan and the imprisonment for life of Patrick Nicholls. Neither, he helped reveal, had committed the murders for which they had been sentenced.
As a driving force behind the organisation created to examine claims of miscarriage of justice, Leigh, who has died aged 89 after a stroke, may have been modest and mild-mannered, but his enthusiasm, high principles and meticulous, case by case examinations resulted in the overturning of numerous wrongful convictions.
Mattan, a British Somali seaman, had been executed in 1952 despite there being no forensic evidence and his having alibi witnesses. Nicholls was convicted in 1975 of killing an elderly woman whom the court of appeal eventually found had probably died of natural causes.
Their supporters’ challenges were not, however, taken seriously until Leigh and his team began scrutinising evidence in 1997. Although a commissioner supervising investigations, he met and interviewed claimants, their lawyers and relatives.
He also popularised the CCRC’s work, explaining to the media that the commission had inherited a backlog of 260 cases and was gathering fresh applications in its first year at the rate of five to six per day.
Other high profile cases Leigh reviewed were those of Derek Bentley, executed in 1953 but subsequently posthumously pardoned; Winston Silcott; James Hanratty; and Ruth Ellis – the last woman to be hanged in Britain. Not all referrals to the court of appeal resulted in convictions being quashed.
He was appalled at the financial restrictions imposed on the CCRC’s resources in recent years, which has resulted in its failure to carry out routine DNA testing.
Leonard was born in Vancouver, Canada in 1935. His father, also Leonard Leigh, was descended from a family that included a Southampton solicitor and the crime writer Dorothy L Sayers. His mother, Lillian Mavis Hayman, was from a Ukrainian Jewish family who had fled tsarist pogroms in the 1900s.
Leonard senior was a mercurial character – variously a salesman, chef, fisherman and smuggler of alcohol across the border to prohibition-era America, until his van was shot up by US border guards.
His son was often farmed out to relatives and attended 13 different schools – sometimes suffering antisemitic bullying – as his parents shuttled around western Canada in search of jobs. Leonard attended the University of Alberta, initially aiming to study history, but switching to law to improve his employment prospects. He paid his way through university by serving in the Canadian infantry during holidays.
After graduating in 1957, he joined a law firm and in 1959 was admitted to the Alberta bar. Specialising in criminal work, he was involved early on in a trial concerning a killing in the Inuit community in Yellowknife, Northwest Territories.
At a party in Calgary, Leigh met his wife, Jill Gale, a British librarian who had trained at the Ashmolean in Oxford and moved to Canada to work for Imperial Oil. They married in 1960. That year he joined the country’s Department of Justice.
Keen to return to academia, he won a Leverhulme Foundation award to study at the LSE in 1962, and four years later gained a doctorate. It became his professional home as he was successively appointed lecturer, reader and then in 1982 professor of criminal law. As head of department, he encouraged women in their academic careers.
His first book was The Criminal Liability of Corporations in English Law (1969). Other publications included Police Powers in England and Wales (1975), The Control of Commercial Fraud (1982) and Criminal Procedure in English Public Law (2005).
A Europhile, he taught himself French and Spanish while establishing LSE’s first degree in French law, which gave students a year abroad in Strasbourg. He also developed legal initiatives on combating fraud in the European Union.
After the fall of the Berlin Wall, Leigh was sent by the Council of Europe to Hungary, Poland and Albania to advise on post-communist legal systems. He failed to persuade Russia to remove a clause in its penal code criminalising “insults” of “representatives of power” – effectively protecting officials and the head of state from criticism.
Following the quashing of the Birmingham Six convictions in 1991, a royal commission on criminal justice was established to investigate miscarriages of justice. Leigh co-wrote its report on comparative pre-trial procedures in France and Germany, concluding that although continental systems were highly effective, introducing an inquisitorial approach into British justice would not work.
When the CCRC was created, he was chosen as one of the founding commissioners. He resigned his LSE chair in 1997 to concentrate on cases that cast a shadow over England and Wales’ vaunted justice system.
“Leonard was very committed to righting injustice,” one fellow CCRC commissioner recalled, “but very robust in dealing with applicants … whose grounds he considered spurious.” Always smartly turned out, he had a dry sense of humour and could be forthright when required. Described by one academic colleague as “possibly the brightest person I have ever met”, he was known by some friends affectionately as “Yoda” – small but extremely wise.
He retired from the CCRC aged 70 in 2005 but continued publishing legal articles, remaining an honorary fellow at Birmingham University until 2010. Moving to Oxfordshire, he became chair of Bloxham village parish council. He enjoyed choral singing and walking, latterly with Angus, his cairn terrier.
Jill died in 2015. Leigh is survived by his son, Matthew, his daughter, Jane, and three grandchildren, Alex, Charlotte and Anya.
• Leonard Herschel Leigh, barrister and academic, born 19 September 1935; died 13 March 2025
