Bürkl was responsible for numerous executions, summary executions and other killings of the Polish Jews and prisoners of the infamous Pawiak prison in Warsaw (including civilian hostages and Soviet prisoners of war), where he was both a Zugführer (guard shift leader) and a deputy commander. Between 1941 and 1943 he personally murdered several dozen people, both in and outside the prison, including during his trips into the Warsaw Ghetto where he shot people at random. During the Warsaw Ghetto Uprising a group of jailers from Pawiak, under the command of Bürkl, volunteered to help in the hunt for the Jews. He was said to be addicted to morphine and was never seen separated from his big German Shepherd Dog named Kastor which he used to terrorize the prisoners of Pawiak. Prominent among his victims was Dionizy Błeszyński, an Armia Krajowa (AK) district commander who was arrested and hanged in 1943.