This is a very odd film, mainly because the story behind it is more important than the film itself. Roger Corman had taken a film crew to Ireland to shoot yet another forgettable B-movie (I forget which one). Among them was a very young sound engineer called Francis Ford Coppola, who had gotten the job because when at the last minute the usual sound man was taken ill, Corman asked if anybody else could operate the equipment, and Coppola put his hand up. Actually that was a complete lie. He just wanted to be part of the movie, and all he knew about sound engineering was what he learned from reading the instruction manual during the flight to Ireland.
Nevertheless, he muddled through, and Corman, who always had an eye for inexperienced young technicians who showed a spark of talent, noticed that his somewhat inept sound man was passionately keen on all aspects film-making, and seemed to be picking up the basics remarkably quickly through sheer enthusiasm. So he made him a very surprising offer. Since Corman, with his usual workaholic super-efficiency, had finished the movie he'd gone to Ireland to make both ahead of schedule and under budget, the entire cast and crew would be getting a paid vacation for the next couple of weeks, which to Corman seemed like a waste. So he told Coppola that if he reckoned he could whip up a script overnight and shoot a movie with the available resources before it was time to go home, he was welcome to give it a whirl.
This incredibly bizarre murder mystery was the result, and given the circumstances under which it was made, it's fair to say that Coppola rose to the challenge magnificently. Actually it's not much of a mystery, since there are only two suspects: the guy who is really obviously flagged as a loony from the start, and the quiet one who wouldn't hurt a fly (have you solved it yet, Sherlock?). But hey, that's what happens when you've got about 12 hours to write the entire script before the cameras start rolling. And for a semi-improvised literally no-budget film, it's genuinely quite gripping, and full of stylistic flourishes. You might not have guessed from these humble beginnings that Coppola would go on to make the Godfather Trilogy, but given what he achieved when Roger Corman basically lobbed a camera at him and said "Make a movie NOW!!!", there was obviously untapped talent there from the start.
This isn't really Coppola's directorial debut, since he made at least one porno movie under a pseudonym, but as far as his PR people are concerned, it's the first film he'll admit to making, and that's good enough for them. At least two cuts of this film exist. If the onscreen title is "The Haunted And The Hunted", it's probably the original version. If it's the one retitled "Dementia 13", crucial scenes may be extremely confusing because the axe murders have been edited out. Hopefully in this day and age the very mild gore has been restored to all available DVD cuts, but you may be unlucky and get an old one. For a better and crazier B-movie about a murderously disfunctional family, see co-writer Jack Hill's utterly bonkers "Spider Baby".