Alphonso DeNoble, who played the Spages' fat pervert landlord, wasn't a professional actor at the time. He was working as a bouncer at a gay bar and the director of the film persuaded him to play the role. Before his death in 1978, he got acting jobs in two other low-budget horror films.
Columbia Pictures was set to release the movie (as "Communion"), but pulled out for legal reasons. When Allied Artists picked it up, director Alfred Sole demanded a title change so that the audience wouldn't think they were seeing a religious film. The book adaption retains the film's original title.
The knife used in the film was created by Alfred Sole's neighbor, who was an engineer, and was designed with a retractable blade. It was the only knife used in the film; the filmmakers never made any duplicates.
Alice's and Mrs. Tredoni's translucent face masks with the eye shadow and red lipstick, were a popular Halloween toy for children during the 1950's, mostly mass-produced to be sold in dime stores. They are still mass-produced by Asian companies and sold worldwide through stores such as eBay.
This film is implied heavily to take place in the mid-1950's. The items such as Annie's Kodak Starmite, Alice's mask and the toy-store Archie comics in the window shop all point to the 1950's since these items were popular at the time. Also in the police station a radioactive symbol can be seen in the background briefly, next to a door, presumably a fallout shelter. Fallout shelters were being built everywhere in the 1950's after the fear of the hydrogen bomb began to arise. This film takes place in the early 60's. In one scene a photo of President Kennedy is shown hanging on a wall. Also, a 1961 calendar is shown in the detective squad room.
Original prints of Alice, Sweet Alice had the title credits with the animated painting of Alice holding the knife that newer digital copies of the film have, but the original title letters still said 'Communion', which, in 1998, was edited to comply with the name it was to be marketed under.
Linda Miller was injured while filming the scene in the hospital, and production had to be halted for a month. Fortunately, she didn't have to go far for medical help since they were filming in a hospital.
The trivia items below may give away important plot points.
In the scene where Dom is attacked by the killer in the stairway at the abandoned building, it was required for the killer to drop the knife after stabbing Dom once and have it land directly on the handrail below, sticking straight up. Director Alfred Sole only had one knife and had to drop it repeatedly, and then have a crew member run back down the stairs to retrieve it and try it all over again. Finally, after over 20 tries, the knife landed directly on the handrail, giving the filmmakers the shot that was needed.
There is a scene half way through the film were Alice grabs a kitten by the neck, twists it the air, and then throws the kitten toward the floor out of the camera shot. This seen was cut from the British release due to the strick animal abuse laws in the United Kingdom.