Wedi iddo ddioddef o gamweinyddu cyfiawnder mewn achos o lofruddiaeth yng Nghaerdydd, penderfynodd Michael O'Brien ymchwilio i achosion enwog ac amheus eraill yn ne Cymru dros gyfnod o ddeng mlynedd ar hugain. Dyma ganlyniad brawychus ei waith ymchwil i bymtheg o achosion, ac i weithgaredd Uned Camweinyddu Cyfiawnder Llu Heddlu De Cymru.
Michael O’Brien was a victim of a miscarriage of justice over a murder in Cardiff. He was driven to discover more about the many notorious and dubious convictions made in south Wales over a period of thirty years. This is the shocking result of his research into fifteen cases, and the Miscarriage of Justice Unit in the South Wales Police Force.