Though Lynda Carter and Jim Carrey did not appear onscreen together in this television film, they both portrayed DC comic book characters (the title role on Wonder Woman (1975) and The Riddler in Batman Forever (1995)). Five years after this television film, Jim portrayed a Dark Horse comic book superhero known as The Mask (1994) which made a name for himself.
This television film features eight deaths (six men and two women). Since an account book, Johnny's diary, and a key on Barbara Leguire's costume had no existences whatsoever, Barbara and Leora were both being dishonest along with Helen. Johnny, Carl, and Brad all believed them. That is what led to their unexpected deaths. Reggie and John only murdered Barbara, Bundy, and Leora.
Michelle Phillips who portrayed Leora in this television film previously appeared in Murder Me, Murder You (1983) as Chris Jameson. Her death in that television film was Michael A. Andrews poisoning through tampered medication; she dies shortly afterwards while testifying in a courtroom. She was not seen taking the poisoned medication, but her apparent "heart attack" in court was shown on screen.
John Calvin who portrayed Doctor Carl Durant in this television film previously had a guest appearance in "The New Mike Hammer" second season episode "Firestorm" as Pete Kingman, but that character remained alive in the episode because Kingman did not end up being a murder victim like Carl Durant did in "Murder Takes All".
Helen murdered both Johnny and Carl (not counting Brad's death) because they both stole money from the foundation in downtown Las Vegas prior to their deaths. That means Johnny and Carl both lied to American television audiences that they were donating money for the "Have a Heart" telethon charity at the beginning of this film. At the end of this film, Mike used Johnny and Carl's money correctly by tossing all of the dollars from Helen's suitcase into the Durant Clinic's telethon bin for Johnny's donation before returning to the New York City borough, Manhattan.