From 1928 until his death he was Gauleiter of Gau Württemberg-Hohenzollern, and from early 1933 held the offices of State President and Reichsstatthalter (Reich Governor) of Württemberg.

Around this time he also joined the Deutschvölkischer Schutz- und Trutzbund, the largest, most active and most influential anti-Semitic organization in the Weimar Republic.

After fierce intra-party fighting, the local Esslingen leader Murr, who attracted attention for his ruthless and unscrupulous methods, was able to oust the incumbent NSDAP Gauleiter Eugen Munder from power.

Early in 1931 Murr introduced his own propaganda newspaper, the NS-Kurier, in which he published numerous editorials which, if not intellectually brilliant, faithfully gave the official party line right up until 1945.

He secretly prepared evacuation measures for Stuttgart, but remained a faithful spokesman for Hitler and Goebbels in public.

On 10 April he called for the city to be defended to the utmost and forbade destruction of tank traps or the raising of white flags under threat of execution and Sippenhaft (detention of an offender's family).

By way of Schelklingen, Kißlegg, Wangen im Allgäu, Kressbronn am Bodensee and further stops, the refugee convoy finally arrived in the Great Walser Valley in the Austrian province of Vorarlberg.

Murr, his wife and two aides stayed at the Biberacher Hütte in the Alps until 12 May, then moved into an alpine cabin overlooking Schröcken.

The arrestees were first taken to Schoppernau, then to Egg, in Vorarlberg, where Murr and his wife committed suicide using poison capsules they had carried with them.

The American occupiers had put Murr on their List of Potential War Criminals under Proposed US Policy Directives and were searching for him.

The Americans and the French soon came to suspect that Murr might be dead, and with the Württemberg police found evidence that led them to Egg.