On 7 February 1933,
Hermann Göring, then the Prussian
Reichskommissar for Interior, appointed Grauert as head of the Prussian police department in the Prussian Ministry of the Interior as the successor to
Erich Klausener. In this capacity, Grauert played a key role in purging the police of opponents of the Nazis in the months that followed and, on 22 February, he was promoted to ministerial director. On the night of the
Reichstag fire of 27–28 February 1933, the Prussian police began rounding up dozens of
Communist opponents of the regime. The next morning, at a meeting at the Prussian Interior Ministry, Grauert proposed the passing of an emergency decree against arson and acts of terrorism to provide legal cover for the mass arrests and to deal with further acts of violence. This proposal was expanded by Reich Interior Minister
Wilhelm Frick to apply to all of Germany by giving the Reich government the right to intervene in any German state that did not maintain order. Thus, Grauert's draft formed the basis for the
Reichstag Fire Decree, which suspended many of the fundamental rights of the
Weimar Republic, thereby eliminating the rule of law and establishing the basis of the Nazi dictatorship. On 11 April 1933, Göring became the Prussian
minister president and promoted Grauert to
state secretary in the Prussian Interior Ministry, while the office of ministerial director passed to
Kurt Daluege. On 1 May 1933, Grauert joined the Nazi Party (membership number 3,262,849) and he joined the
Schutzstaffel (SS) on 2 June 1933 (SS number 118,475) with the rank of SS-
Oberführer. On 22 June 1933, as state secretary, Grauert issued the orders for the establishment of the
Börgermoor concentration camp where hundreds of the regime's opponents were incarcerated. On 11 July 1933, Göring appointed Grauert to the recently reconstituted
Prussian State Council. On 2 October 1933, he became a founding member of
Hans Frank's
Academy for German Law and he was made chairman of its Committee on Police Law. When the Prussian Interior Ministry was merged with the Reich Interior Ministry under Frick on 1 November 1934, Grauert remained a state secretary in the combined ministry. On 20 April 1935, he was promoted to SS-
Brigadeführer. == Removal from office ==