I have never felt so strongly the presence of two contrasting characters as when I interviewed Harris. For much of the interview he performed, just as he did in court – he sang, he laughed in that exaggerated way, he whispered in that exaggerated way, he drew me a miniature flick cartoon book. Then, when he wasn’t performing, he was miserable as sin.

Whereas Clifford and Savile never appeared to question their essential goodness as men and altruists, Harris hated himself. He talked about what a useless father he’d been – selfish, paying more attention to strangers than to his wife and daughter, chasing his own dreams and desires, ignoring those of his family. He had recently written an autobiography and it had forced him to reassess his life. “You start writing it by thinking what a great guy I am. I’ve done this, that and the other. Then you suddenly think it’s all been inward focussing, only me, me, me, me, me, me, me, and people who are really close … ” I never began to suspect why he was so tortured. At the time he came across as a man with humility, in touch with his flaws. But in retrospect, I think even here he was indulging himself – only this time, it was his guilt rather than his libido

The very thing that makes true crime compelling – this really happened – also makes it distasteful: the use of human agony for the purposes of entertainment. Of course, what is the novel if not a voyeuristic enterprise, an attempt to glimpse inside the minds and hearts of other people? But with fiction, no actual people are exploited in the making.

I love crime fiction, too, but lately I’ve come to appreciate true crime more, specifically for its lack of certain features that crime fiction nearly always supplies: solutions, explanations, answers. Even if the culprit isn’t always caught and brought to justice in a detective novel, we expect to find out whodunit, and that expectation had better be satisfied.