This is one of the few times a true story is nearly made unbelievable by the idiotic cast of characters. Fortunately, the presence of Patty Duke holds it together somewhat, although for most of the movie, she's as bad as everyone else. It seems that everyone in the world is completely blind to the fact that the real killer is the loon that they've decided is their friend... they miss things like "Jenny told her in a dream," and "You need to go kill him, he did it. And bring me a finger to prove he's dead." Of course, she's not going to just join the lynch mob/family... she's apparently going to wait at home. If you want to know the story, which is tragic, but interesting, read the book... don't waste your time on this movie unless you've nothing else to do and you're snowed in.
