I am grateful to many people who have helped directly or indirectly: first and foremost, Hélène Mulholland, for her invaluable and diligent research work; my agent, Andrew Lownie; Jennie Condell and Pippa Crane of Elliott and Thompson, and also, in no particular order: Roy Greenslade, Kate Macleod, Mark Olden, Alistair McClure, James McClure, David Jenkins, Karen Payne, Matthew Engel, Amber Marks, Jonathan Green, Stuart Christie, Ferdinand Dennis, Stella Coradi, Julia Quenzler, Clare Longrigg, the late Bobby King, Richard Adams, Alan Campbell, Peter Clark, Jason Rodriques, Luc Torres, Katy Stoddard, Lorna Macfarlane, the late Professor Andrew Huxley, Nick Davies, John Lloyd, Mark Sullivan, Christopher Sheppard, Bob Woffinden, Richard Norton-Taylor, Nick Reynolds, Ruby Crystal, Bruno Vincent and, particularly, all those who agreed to be interviewed on the record or off the record (a term that Lord Justice Leveson understandably found confusing – I always thought it meant that you could use the information but make sure it was untraceable; others believed it meant not for use at all. Too late and too bad if I got it wrong).
I am also grateful to the staff of the British Library, to James Hamilton of the Signet Library in Edinburgh, and the staffs of the National Archives, the Scottish National Library, the British Museum, the Wellcome Collection, the Guardian Library, the British Newspaper Archive, the Dickens Museum, the BBC Archives, the oldbailey online, History Today, the Broadway Bookshop, Harvard University, Wikipedia, Murderpedia. org, Press Gazette and Gentlemen Ranters. My thanks also to the Guardian, Observer, New Statesman, the Oldie, Esquire, British Journalism Review and the Journalist for whom I wrote about some of the subjects addressed in this book. I have tried to credit any information that I have found in books – see the Bibliography – and articles. If anyone has been omitted, my apologies; all I can suggest is that they buy many, many copies of this book to ensure its republication which would then, of course, include suitably amended attribution.