A few days after Germany invaded the USSR, Lviv was captured by the Wehrmacht. German authorities planned to murder members of Polish intelligentsia in Lviv. In order to avoid the complications that had previously resulted in the mass arrest of professors in Kraków in 1939, the Germans decided to organize the immediate shooting of professors from Lviv universities, a large number of which were active during the Soviet occupation of the city. The list of names of Polish professors was most likely made and delivered to Germans by Ukrainian students from Kraków, associated with the Organization of Ukrainian Nationalists (OUN).