"The Amityville Horror" is a horror novel from 1977 by Jay Anson. Based on this book there has been a series of films around 20 years after the release of the book. The novel is claimed to be based on a true story but many people doubt of its truthfulness.
The Amityville Horror is a true story that marked the history of the United States in the 1970s and caught Hollywood's attention and elevated a house on the outskirts to one of the most terrifying haunted houses of the twentieth century.
The book, and therefore the movies, are based on the paranormal experiences of the Lutz family in a house in Amityville. This family moves into the house around a year after the "DeFeo murders" - Ronald DeFeo Jr. killed six of his family members in this house on November 13, 1974.
The quotes listed in this post are all from "The Amityville Horror" movie.