The marriage was witnessed by Regina's mother's stepfather Adolf Lachmann of Lange Strasse 42 and half-brother Artur Lachmann of Dyngosstrasse 20. At the time of the marriage, Boris was living with Adolf at Lange Strasse 42. Eight years later when Boris reported Artur's death, Artur was living at this address while Boris gave his address as Dyngosstrasse 20. When Boris reported Adolf's death the following year, both Adolf and Boris were living at Dyngosstrasse 20.