Who killed murder?

Pity the poor crime writers. Our earnings, like those of all authors, are diminishing for reasons far beyond our control. Our fictional criminals and detectives are being outsmarted by genetic fingerprinting, omnipresent security cameras and telltale mobile phones. Who needs Sherlock Holmes to solve a tricky crime when you have computers, with their unsporting ability to transmit and analyse enormous quantities of data and identify culprits? But the bigger problem for us novelists (if not for everyone else) is that murder itself is dying.

The official homicide rate peaked in 2002, thanks to Dr Harold Shipman, and has since fallen by half — from 944 then to 517 last year. Adjusting for population, murder is now at the same level it was in the last years of Queen Victoria — and, in spite of what Arthur Conan Doyle led readers to believe, the streets were pretty safe then. The murder rate started to rise in the 1960s and soared in the 1990s, which caused widespread panic. Family breakdown, collapsing morals and a feral underclass were all blamed for an apparently inexorable increase in violent crime.

But then that rise stopped, and the murder rate began to nosedive. Why? Or, as we crime writers say, whodunnit?

Investigating the murder of murder is difficult, especially when statistics derive from a variety of sources. This is not just a British phenomenon. Homicide rates throughout the industrialised world have declined during the past century. The fall in Britain, the USA and Canada is particularly marked — these are all countries where the rate increased in the 1960s and 1970s. And it isn’t just murder. Over the past 20 years robbery has declined almost as much as homicide, and vehicle theft more so.

Prosperity is often fingered as the prime suspect, the idea being that the economic boom of the 1990s suppressed many of the conditions in which crime flourishes.