About the ending (spoilers)
In the film, Patty (Libby's mother) seemed like a smart, rational person.In the end, it turns out that she agreed to be murdered so her son and daughters would get insurance money. And she did this, to protect her family. So, she pretty much let a homicidal maniac come into her house in the middle of the night... to protect her family. Riiiight. Is she brain damaged or something? Is there something in the book (that is not in the movie) that helps explain this absolutely colossal nonsense?
And I know the agreement was that only she would be murdered and her kids getting killed was just kind of an accident, but how can you trust a murderous stranger with the life of your kids in the first place? It doesn't make any sense.
"Ok, psychotic killer whom i just met, i will give you my adress and let you come into my house (where my children are sleeping) in the middle of the night and kill me, but no touching my kids. So, no messing around with my kids after I'm dead and can do nothing about it, you psycho-dude who freaking kills people for pleasure. Do we have a deal?" Yeaaaaah, are we seriously expected to believe that's the reasoning of someone who is not completely insane?