Heinrich Müller was a German police and SS official who headed the Gestapo from 1939 until the final days of the Third Reich. As a senior official of the Reich Main Security Office, he was deeply involved in political repression, counter-intelligence and the Nazi persecution and murder of European Jews. He disappeared in Berlin at the end of the war and his death is generally presumed to have occurred in May 1945.
In John R. McKay’s In For The Kill, Müller appears under his historical identity as the Gestapo chief who assigns security around a fictional secret facility in the Netherlands. His office and authority are historical, but the particular mission, subordinates and conversations used in the novel are fictional reconstruction.