Everybody talks about foul dens and filthy slums in which crime can run riot; but it's just the other way. They are called foul, not because crimes are committed, but because crimes are discovered. It's in the neat, spotless, clean and tidy places that crime can run riot; no mud to make footprints; no dregs to contain poison; kind servants washing out all traces of the murder; and the murderer killing and cremating six wives and all for want of a little Christian dirt.
G.K. Chesterton, The Complete Father Brown
crime