born in augsburg, burger was a machinist by trade. burger was a member of the nazi party from the age of 17. burger immigrated to america in 1927 and became a u.s. citizen in 1933. he had lived in the united states for some years, even serving in the national guard. during the depression, burger returned to germany, he rejoined the nazi party and became an aide-de-camp to ernst roehm, the chief of the nazi storm troopers. later, he wrote a paper critical of the gestapo—a move that earned him seventeen months in a concentration camp. despite his history as a survivor of a nazi internment camp and harassment of his wife by nazi party members, burger was recruited by the abwehr, nazi germany's intelligence organization. he took part in operation pastorius, a plan by which eight german saboteurs were to be transported by u-boat to the united states. burger and the others landed with the intention of damaging united states economic targets.