The organisation continues to represent 15 prisoners including the last British resident in Guantanamo Shaker Aamer.
Reprieve continues to tackle cases of torture involving "extraordinary rendition," and most recently US drone attacks in Pakistan.
However, the British-born Stafford Smith began his career defending death row inmates in the US, a role the charity still performs to this day.
His 2007 book Bad Men was a damning indictment and incendiary expose of the cruelty and bureaucracy at work behind the wire in Guantanamo and the closed doors in military tribunals.
His new book Injustice: Life And Death In The Courtrooms Of America does the same for the death penalty. It is by parts a furious denunciation of the barbaric practice, a forensic dissection of the bizarre nature of the US legal system and a plea for sanity.
Stafford Smith is blunt in his assessment of a system set up to convict, and in which proof of innocence is not always a defence.
Prosecutors lie, defence lawyers are frequently inept and judges have been shown on more than one occasion to take bribes.
The book is also the story of British businessman Krishna Maharaj, framed, Stafford Smith believes, for the double murder of a former business associate and his son in Miami in 1986.
The case is both tragic and appalling. Failed by his defence lawyer - who actually advised his client not to call alibi witnesses as they seemed too concrete - Maharaj was found guilty on perjured witness testimony and sentenced to death.
It was while he languished on death row that Stafford Smith took up his case, free of charge, and through laborious and gruelling investigation unearthed evidence suggesting the victims, the Moo Youngs, may have been involved in laundering money for - and skimming from - a Colombian drug cartel which he convincingly argues provides a much more plausible explanation for their killings.
He also made a series of staggering discoveries about his client's original trial, whose judge was arrested on bribery charges part way through the proceedings.
But incredibly Maharaj's lawyer Eric Hendon advised him to waive his right to a new trial.
In a second alarming development it emerges that the replacement judge had the unsigned order of execution drawn up by the prosecution before he had even heard the evidence.
As Stafford Smith notes: "Krishna had been convicted and sentenced to death, with one judge in shackles and the other chumming up with the prosecutors in secret."
Despite the mountain of evidence showing the unfairness of his trial, a seemingly concrete alibi and a plausible alternate theory for the murders, Maharaj was not granted a retrial. His death sentence was commuted to life imprisonment and he remains incarcerated today, 26 years on.
As Stafford Smith is amply able to illustrate, while this was an appalling miscarriage of justice it is far from unique. His anger in the face of injustice is evident, but so too is his compassion.
And while strong in his condemnation of both the system as a whole and specific individuals, he is equally unflinching in his self-criticism.
As previously evidenced in Bad Men, the author has a knack for being able to combine explanations of complex legal issues with an entertaining, gripping and witty narrative.
This book will leave you angry, bemused and frustrated. But it will also make you glad that there are individuals like Stafford Smith who have dedicated their lives to fighting the inherent injustice of the system both in the US and here.
Bad Men remains perhaps the definitive account of Guantanamo and the battles faced by lawyers to defend their clients.
Similarly, anyone wishing to get an insight into the death penalty and the US legal system would do much worse than to start with this book.
Source: Morning Star