Murder, you see, is an amateur crime. I’m speaking of course of the kind of murder you have in mind – not gangster stuff. One feels, very often, as though these nice ordinary chaps had been overtaken, as it were, by murder, almost accidentally. They’ve been in a tight place, or they’ve wanted something very badly, money or a woman – and they’ve killed to get it. The brake that operates with most of us doesn’t operate with them.