The Gestapo (Secret Police) were set up by Hermann Goering in 1933 as a non-uniformed secret police force. By 1936, it was run by Himmler’s deputy, Reinhard Heydrich.
The main aim of the Gestapo was to identify opponents of the Nazi government through spying, tapping phones and, most effectively, a network of informants.
There were only about 30,000 Gestapo officers for a population of 80 million, so they relied on people’s fear of not knowing who was in the Gestapo.
By 1939 the Gestapo were arresting 160,000 people a year for ‘political crimes’. It is estimated 80% of these were discovered through the informant network rather than the Gestapo officers themselves.