In the 1960s, he was an armed robber who was tagged "Public Enemy No. 1" by Scotland Yard. He was apprehended and given a 23-year jail sentence. He escaped from prison on several occasions and after his final re-arrest in 1970 he was given a sentence of 26 years. He was paroled in 1978.
In 1998 he lost a libel action brought by sprinter Linford Christie over his claim that Christie was a "steroid athlete". Six months later, Christie's track career was ended when he received a two-year ban for taking a performance-enhancing substance.
In 2002, McVicar published a book about the Jill Dando murder, Dead on Time, in which he paints the convicted killer Barry George as a sophisticated liar, trying to appear too stupid to carry out a difficult mission. The book appeared after George's first appeal was rejected. (The conviction was overturned in 2008, and George released.) McVicar wrote Who Killed Jill? You Decide, in which he examines the British jury system. This second book is purged of the chapters recounting 'personal experiences' which McVicar claims were the product of poetic licence for the most part.