Dramatic reconstruction and interview footage combine to reveal how Birmingham family man Brian Field was convicted for the sadistic killing of a Dorking schoolboy 33 years after the event. In 1968, nobody knew this outwardly respectable and well-liked gardener led a depraved secret life, and only a chance encounter with police on a motoring matter provided the DNA evidence needed to convict one of the country's most dangerous paedophiles (thetvdb.com)