Overview: Twenty years from now, the media is reporting record low levels of violent crime. In this world, Liam, a hard-to-control youngster, has failed preliminary tests to establish the scale of his problem. He will be treated, but how hereditary is violent behaviour? This drama-documentary, based on rigorous research and including interviews with experts in the field, explores to what extent potential violent behaviour can be identified by clinical testing. A debate on the issues raised follows. Writer: Mark Hayhurst Director: Carl Hindmarch Producer: Roy Ackerman