invasion of the Soviet Union and the eastern half of prewar Poland fell under German occupation in place of that of the USSR. One of the earliest Nazi crimes in Lwów was the mass murder of Polish professors together with some of their relatives and guests, carried out at the beginning of July 1941. Killings By 2 July 1941, the individual, planned executions continued. At approximately 3 o'clock in the afternoon, Professor Kazimierz Bartel was arrested by one of the Einsatzgruppen operating in the area. During the night of 3/4 July, several dozen professors and their families were arrested by German detachments – each one consisting of an officer, several soldiers, Ukrainian guides and interpreters. The lists were prepared by their Ukrainian students associated with OUN. Some of the professors mentioned on the lists were already dead, specifically Adam Bednarski and Roman Leszczyński. Among those arrested was Roman Rencki, a director of the Clinic for Internal Diseases at Lwów University, who was kept in an NKVD prison and whose name was also on the list of Soviet prisoners sentenced to death. The detainees were transported to the Abrahamowicz's dormitory, where despite the initial intention to kill them, they were tortured and interrogated. The head of the department in the Jewish hospital, Adam Ruff, was shot during an epileptic attack. In the early morning of 4 July, one of the professors and most of his servants were set free while the rest were either brought to the Wulka hills or shot to death in the courtyard of the Bursa Abrahamowiczów building. The victims were buried on the spot, but several days after the massacre their bodies were exhumed and transported by the Wehrmacht to an unknown place. There are accounts of four different methods used by the German troops. The victims were either beaten to death, killed with a bayonet, killed with a hammer, or shot to death. The professors themselves were shot to death. Responsibility The decision was made at the highest level of Nazi Germany's leadership. The direct decision maker of the massacre was the commander of the Sicherheitspolizei (Befehlshaber der Sicherheitspolizei und des SD- BdS) in Krakau District of the General Government, Karl Eberhard Schöngarth. The following Gestapo officers also participated: Walter Kutschmann, Felix Landau, Heinz Heim (Chief of Staff Schöngarth), Hans Krueger and Kurt Stawizki. None of them were ever punished for their roles in the Lwów