In December 1968 Mary Bell, aged eleven, appeared before a criminal court in England, accused of murdering, Martin Brown, aged four, and Brian Howe, aged three. Mary was found guilty of manslaughter due to diminished responsibility and was sentenced to 'detention' for life. What would induce a young child to murder two other young children? In this short book, Sylvia Perrini, looks at Mary's tragic life, her years in prison and life since prison.