In general, I don't agree with those who have condemned neighbours, extended family, Elvis*, etc., for not reporting. It's easy for us to say, with hindsight, what they should have done. But the fact is that most people have to cross a huge psychological distance to get from "hmm, that's a bit hinky" to"A crime is being committed and I must report it." This is especially true when whatever's going on involves other people's private lives. We also don't know how the bystanders viewed family relationships in general, or whether they had any reason to distrust the police or social services.
But I do wonder why relatives never checked up on the older kids once they reached adulthood. Did no one think, "Hmm, my niece must have graduated high school by now, I think I'll look her up and try to get to know her without my crazy sister interfering?"
On a vaguely related note - were the older boys registered for Selective Service? If not, did the government follow this up?
* Don't know if anyone on WS has blamed him, but I've seen comments elsewhere that did.
