identify this movie - Horror story writer moves with his family into a house where the previous family was murderered

I watched a movie a few months back. The movie starts with four people hanging by their necks on a tree. The hero is a writer of horror stories. He comes to a house along with his family. He finds a projector with several film rolls on the attic. He watches those films everyday. All films were based on a murder case. The movie's investigation goes like this:

A child in the house gets haunted. He kills the family members. Well, they say something that the children do that as a devotion to some god. The interesting link between every murders is that the murdered family had stayed for a while in a house where people were previously murdered. The story goes on like the next family stay in this house and go to another house where they get murdered by their children.