Sister, my Sister is based on the same story as a movie called Murderous maids.
It's a cheeseball name but a great film.
You can wiki the story of the Papin sisters, who worked as maids in France many years ago and greatly resented their working conditions...and...well...did something about it. I really loved Murderous Maids, it was a top notch film, it wasn't all about murder, it was also about being poor and troubled and put upon.
Actually, i figured out how to do the links...here is the story of Christine and Lea Papin on wiki
They were 2 French maids who murdered the lady of the house and her daughter, and many felt it was symbolic of class struggle, which is the film's take on it....the crime itself was escpecially disgusting.
No ghosts, demons, or otherworldly happenings. Just a psychotic teenager with a vivid imagination trying to get off with an insanity plea, and some enterprising con-artists trying to cash in on a gruesome murder.
This is an excerpt from the linked article above:
"In the end, this tale of horror and demonic possession was debunked by the Catholic Diocese of Rockville Center, the Amityville Police Department, William Weber (Butch DeFeo's defense attorney), U.S. District Court Judge Jack Weinstein, and even George and Kathy Lutz, who ended up recanting certain parts of the tale. The new owners of 112 Ocean Avenue in Amityville were disturbed by no other visitors than the hordes of curious onlookers, and those convinced that theirs was a haunted house. This entire fabrication detracted from what was in fact the true horror of Amityville, the cold-blooded murder of six innocent people by one of their own family members."
Icantworkwithyou,
I have always been captivated by the Joanne Lees story.
There is also a wiki on it.
A tragic and fascinating story, it's easy to see why so many did not believe her.
Sometimes truth is stranger than fiction.