Abraham Polak was born in Leeuwarden, a son of Levij Polak and Heintje de Beer. He was unmarried and an office clerk by trade. Before he moved to Amsterdam, Abraham resided in Den Haag at various addresses where he was registered as a commercial clerk. On 27 December 1918 he was registered as living at the address Gerard Doustraat 198 ground floor in Amsterdam where since 1911 the couple Louis Sw…