They might have known something about Tate. Polanski of course was married to her and she had been doing some movies about vampire culty stuff. (There is a connection between Tate/cult movies/ and another actress with a weird background that is important here but I cant remember). Of course there is all that blood drinking going on and we know what Roman Polanski became famous for. Kinda has to make one wonder what the truth was regarding those murders...
I think you’ve made the connection. Tate-Polanski.