Only when he has the answers to these questions can he address the fifth: who is responsible? What he searches for at the crime scene are not frinerprints, fibres or bloodstains - he looks for the 'mind trace' left behind by those responsible: the psychological characteristics that can help the police to identify and understand the nature of the perpetrator.

The Jigsaw Man is not only a detective story involving some of the most high-profile cases of recent years, but also a journey of discovery into the darkest recesses of the human mind to confront the question 'Where does crime come from?'