Mary Bell, the younger but infinitely more sophisticated and cooler of the two, was found guilty of manslaughter. She evaded being branded as a murderer due to what the court ruled as 'diminished responsibility', but she was sentenced to 'detention' for life.Step by step, Gitta Sereny pieces together a gripping and rare study of a horrifying crime; the murders, the events surrounding them, the alternately bizzare and nonchalant behaviour of the two girls, their brazen offers to help the distraught families of the dead boys, the police work that led to their apprehension, and finally the trial itself. What emerges from this extraordinary case is the inability of society to anticipate such events and to take adequate steps once disaster has struck.