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.