Nazi official and high-ranking member of the SA and SS. Between 1939 and 1943 he was SS and Police Leader in the General Government in German-occupied Poland and in that capacity he organized and supervised numerous acts of war crimes.
He became member of the Nazi party in 1929, of the SA in 1930 and of the SS in 1931. In 1939, he cumulated the functions of supreme head of the police and the SS (HSSPF) in Cracow and of responsible for security in the General Government (May 1942). He was appointed in this latest function when systematic mass killing of Jews in the districts of Lublin and Galicia were extended to all districts of the General Government. This is when the death centers Sobibor and Treblinka were created while Belzec was momentarily closed in order to improve its capacities for mass murder. On June 3, 1942, Krüger received the confirmation of his nomination. He was also informed about his new mission: handle all “Jewish affairs” (Judenangelegenheiten). On June 18, 1942, in Lublin, Himmler met Krüger and Globocnik, the coordinator of the Reinhard Operation. During the meeting, they discussed the extermination operations and Krüger received the order to keep an eye on the resettlement process. Himmler asked him to complete it before the end of the year. Krüger used the police and the SS to evacuate Jews from the ghettos. In June, for example, a first action was organized against the ghetto of Tarnow. Krüger ordered the local SD (security police) to “clean” the ghetto. The SD leant upon the Waffen SS and other Polish units. The second action took place on July 24, 1942. Jews who were not killed on the premises were deported to Belzec. The last action ended on September 12 and all Jews were then deported to Belzec. The liquidation of the ghetto of Tarnow was operated in August 1943 under Wilhelm Koppe’s direction (he was Krüger’s successor). Krüger coordinated the operation Erntefest. In October 1943, Himmler ordered the SS (with the help of a commando coming from Auschwitz) to eliminate all Jews coming from the labor camps of Trawniki, Poniatowa, Majadanek and other smaller camps located in the Lublin district that were considered as provisory. When the Warsaw ghetto was liquidated in April-May 1943, the SS general Stroop reported first to Krüger about the events. Although Krüger had proved his efficiency in killing operations, he lost his function in November 1943 because of a conflict between Himmler and Hans Frank. He was appointed to the command of a SS division in Yugoslavia.
He committed suicide in upper Austria on 9 May 1945.

Link to Wikipedia biography