I saw a segment about a lady who escaped from a family run as a cult by an Afro-American man in San Francisco. She'd been recruited in by one of his other "wives" on the pretext of having her astrological chart done, then it escalated to massage and sex. This man had several such wives, and kids by them. He smoked a lot of crack and one of the The lady had 3 kids, one of whom died. She took the other two and ran away. What was the unsolved mystery? I keep thinking it was that the man got one of her children back and then the child vanished.

I'm dead certain this is something to do with Winnfred Wright. All the details match. But the disappearance of the child is not mentioned in the newspaper articles I can find.

I believe the child you are talking about is Alexander Sol Olive. The father figured out when his "wives" were ovulating (this is where the astrological chart comes in because it involves the date of her last period) and impegnated them. From what I understand, he came to believe that the child was possessed or something, and began to abuse him. One day he hit the child so much that the child stopped moving, and witnesses saw him carry a child-sized bundle of blankets out to his car and drive away. I think they assume that the child was murdered by the father, but I don't know if it's ever been proven.

I don't know if this is the case you are referring to, but it sounds similar.