[11][12][13] According to the Warrens, in the year 1970, two roommates claimed their Raggedy Ann doll was possessed by the spirit of a young girl named Annabelle Higgins.

The Warrens took the doll, telling the roommates it was "being manipulated by an inhuman presence", and put it on display at the family's "Occult Museum".

[14] In 1971, the Warrens claimed that the Harrisville, Rhode Island home of the Perron family was haunted by a witch who had lived there in the early 19th century.

[15][16] The Warrens are best known for their involvement in the 1975 Amityville Horror in which New York couple George and Kathy Lutz claimed that their house was haunted by a violent, demonic presence so intense that it eventually drove them out of their home.

[12] In 1979, lawyer William Weber stated that he, Jay Anson, and the occupants invented the horror story over many bottles of wine.

While a number of independent observers dismissed the incident as a hoax carried out by "attention-hungry" children, the Warrens were convinced that it was a case of "demonic possession".

Ed and Lorraine Warren had been called prior to the killing to deal with the alleged demonic possession of the younger brother of Johnson's fiancée.

In 1986, Ed and Lorraine Warren arrived and proclaimed the Snedeker house, a former funeral home, to be infested with demons.

Horror author Ray Garton, who wrote an account of the alleged haunting of the Snedeker family in Southington, Connecticut, later called into question the veracity of the accounts contained in his book, saying, "The family involved, which was going through some serious problems like alcoholism and drug addiction, could not keep their story straight, and I became very frustrated; it's hard writing a non-fiction book when all the people involved are telling you different stories".

[26] Pennsylvania residents Jack and Janet Smurl reported their home was disturbed by numerous supernatural phenomena, including sounds, smells and apparitions.

The Warrens became involved and claimed that the Smurl home was occupied by four spirits and also a demon that allegedly sexually assaulted Jack and Janet.

The Smurls' version of their story was the subject of a 1986 paperback titled The Haunted and television film of the same name directed by Robert Mandel.

According to Penney, when she became pregnant, Lorraine persuaded her to have an abortion because the birth of a child would become a public scandal and could ruin the Warrens' business.

[citation needed] According to a 1997 interview with the Connecticut Post, Steve Novella and Perry DeAngelis investigated the Warrens for the New England Skeptical Society (NESS).

Novella responded, "It takes work to do solid, critical thinking, to actually employ your intellectual faculties and come to a conclusion that actually reflects reality ... That's what scientists do every day, and that's what skeptics advocate.

"[10] In an article for The Sydney Morning Herald that examined whether supernatural films are really based on true events, that investigation was used as evidence to the contrary.

What we found was a very nice couple, some genuinely sincere people, but absolutely no compelling evidence..."[36] While it was made clear that neither DeAngelis nor Novella thought the Warrens would intentionally cause harm to anyone, they did caution that claims like the Warrens' served to reinforce delusions and confuse the public about legitimate scientific methodology.

[37] In addition to the investigations, Lorraine ran the Warrens' Occult Museum (which closed to the public in 2019)[38] in the back of her house in Monroe, Connecticut, with the help of her son-in-law, Tony Spera.

[42] Over the years, several films and series have been released that are based in part or in full on the paranormal investigations or events that the Warrens are said to have witnessed and described.