Supergrasses – professional criminals, often armed robbers, who were caught red-handed and willing to turn informer against their fellows in return for a reduced sentence – were a hugely valuable crime fighting asset during the 1970s and ‘80s.

But this is the riveting inside story of a supergrass with a difference. Donald Walter Barrett was caught for a serious offence and, having turned supergrass, received a reduced sentence and then, following his release went on to commit more ruthless armed robberies amounting to £1.6 million. The more shocking involved the use of proxy bombs where an explosive device was attached to the victim who was told it would be detonated by remote control if he failed to comply with the robbers’ demands. Using this method, Barrett took an employee of a cash depository and his family hostage overnight, before raiding the depot and stealing £480,000 cash.

Following his sensational arrest for a robbery of gold bullion, Barrett became the Metropolitan Police’s one and only double Supergrass. The Author, a much published and respected crime writer, was one of the Met Flying Squad officers who debriefed Barrett.

The thrilling book features Barrett’s wide-ranging associates including ‘Bertie’ Smalls and ‘The Wembley Mob’, George Ince (whose lover, Dolly Kray provided an alibi) and a whole assortment of colourful and professional career criminals.