In May 1933, the Munich prosecutor's office, not yet assimilated to Nazi policy in the Gleichschaltung process, began investigating the murder of several prisoners at Dachau, prompted by the formal complaint of Sophie Handschuh, who wanted to know the true cause of her son's death at the camp.[3][4][non-primary source needed] Rumors were already widespread about harsh treatment of those under detention and Himmler was forced to refute those claims, even while announcing the opening of Dachau.[3] Wäckerle and Himmler had charges of murder filed against them, prompting Wäckerle to be removed from his position, but these were later dropped after the chief prosecutor and his assistant were each transferred to other offices.[5] Himmler continued his efforts to establish summary execution, then in practice only at Dachau, as a legitimate form of punishment.