On 13 or 14 March 1938, on Heydrich's orders, Böhme murdered Wilhelm Freiherr von Ketteler by drowning.

On 30 January 1936, he was promoted to SS-Hauptsturmführer, then appointed SS-Sturmbannführer on 20 April 1937, and in 1938 became SS-Obersturmbannführer und Oberstleutnant der Polizei.

After the occupation of Czechoslovakia in spring 1939, Böhme was appointed the SiPo (Security Police) chief for the Protectorate of Bohemia and Moravia, based in Prague.

As part of Sonderaktion Prag on 17 November 1939, Böhme was instrumental in the closure of Czech institutions of higher learning and the deportation of 1,500 students to Sachsenhausen concentration camp.

After the assassination of Reinhard Heydrich in May 1942, Böhme – since 21 October 1941 with the rank of SS-Standartenführer – immediately acted on the "retaliation" orders from Adolf Hitler by perpetrating the massacre at Lidice.

Shortly after their arrival in Łódź, officials from the Central Race and Settlement branch chose seven children for Germanisation.

From January to August 1943, he led the Einsatzgruppe B, which perpetrated the mass murder of civilians in the Soviet Union.