Promoted up to Brigadier general, he was deputy to Lieutenant General Arthur Edward Grassett's, chief of European Allied Contact Section in the SHAEF staff of General Dwight Eisenhower.
According to SHAEF regulations, Rauch should have been automatically arrested due to his SS rank, but he was not interned until 27 November when a special Counter Intelligence Corps agent seized and interrogated him at Tegernsee city jail.
In February 1945, when the defeat of Germany appeared imminent, the Supreme Headquarters Allied Expeditionary Force (SHAEF) was provided with a mandate for dispatching troops whose mission would be to secure the safety of Allied Prisoners Of War and to provide for their early evacuation.
By December 1944, SHAEF had established itself in the Trianon Palace Hotel in Versailles, France.
At that time he was transferred to the newly formed G-5 Civil Affairs Division at Supreme Headquarters Allied Expeditionary Force, Europe (SHAEF).