Some say this is a true story. Others say it’s a bunch of bullshit. I favor the second perspective but never mind, it’s an entertaining story.
The tragedy that sparked the story is true – A young man kills his family in the Amityville house. Included in the slaying are his parents and siblings. Years later the Lutz family purchases the house. They said it was haunted, not by your average house ghost but by demonic forces. The book, written in a diary format, covers more ground than the movie does. There are so many more paranormal occurrences in the book and I wonder why the film omitted so much. Anyway, the book is better and if you want to read a more detailed comparison between the book and movie, read this article here: Amityville Horror Book and Movie
The Books of Daniel 