I waded through a lot of the threads in that kink, there is just something so creepy about this house and the murders and some very odd co-incidences. There must be either an incredibly dark story behind all this , or that famikly was just very very very unlucky.
Built in the 1930, according to the 1930 census records, the house was rented ( not owned by, strangely enough) film director/actor Frederick Zelnick, one of the most important producers-directors of the German silent cinema. He also appeared on screen as an actor. Zelnick there with his actress wife , Lya Mara and a few German servants they brought with them. The census records for all other houses list the house owners, architects, designers, who built it etc etc ... this house has none of those facts , simply listed as "unknown".
Friedrich Zelnik was born in a Jewish family in Czernowitz, today in Ukraine, at the time the capital of the Duchy of Bukovina in the Austrian part of the Austro-Hungarian Monarchy. Czernowitz has been then largely populated by Jews and has been after Wilno the most an important city for the Jewish culture in Eastern Europe. IThe Ze;nicks rented the house briefly in 1930 before returning to Germany where he produuced the first talking picture in Europe, He died in London in 1950.
Dr Perelson ( who was Jewish btw , so the Christmas tree is odd but not that unheard of, even back then ) his parents came from the same area of old Austria-Hungary, the city of Cernowitz, and did his wife familt , her maiden name was Silver , and it is quite likely their families were related to Zelnicks, but no links directly link them .
The daughter who escaped her fathers murderous rampage with a skull facture , Judye Perelson ,is now a semi-famous jewelry designer named Judith Handler , she makes very high end clunky lucite style bangles which are famed for the esoteric eastern occult symbolism in the design.
Dr Perelson main area of expertise was the cause of and treatment for headaches, in fact he had a paper published in 1947 medical journal, how ironic he bashed in his wife's head with a hammer , and his daughter now employs lots of heavy hammering into some of her mysticism eastern occultism inspired jewelry making process. ( thats her in the link wearing an example)
There is a lot of other weirdness in that forum, nothing concrete , but the movie being made about that house and its history have a lot of material to work with .
