This feature-lengt (one and a half hour) episode of Shock Docs is frequently listed amongst Amityville films on sites for some reason.
The gimmick is, to insert as much archive footage as possible.
Structuraly, we sepnd 10 minutes on the DeFeo murders, 40 minutes on the Lutz's living in the house, and 50 minutes on that age's paranormal investigations. The curious thing is, while the docu is very much leaning on the "bigfoot is real" tone, at 1 hour 10 minutes it literaly spells you out the whole story of the Lutz was a hoax in hope of not loosing the property.
Confirmation-link: https://www.imdb.com/title/tt13183174/?ref_=fn_al_tt_3