Modern historians think that there was an increase in crime in the period from about 1780 to the mid-19th century. Certainly people at the time thought there was, and there was much discussion of the causes. Governments were busy passing laws to deal with crime - Sir Robert Peel, the recipient of the letter from which the sources in this Case-Study are taken, was preparing the 1829 Metropolitian Police Act (see Gallery Prevention before 1450), even as it was being written. Those who were worried about an increase in crime put forward their favourite theories, as now.