A Sudden Vengeance

David Cass, former private detective turned writer, is asked by a friend to find her missing 18-year-old younger sister, Fran. He finds the girl living with Richie Remick, a local lowlife who runs strip clubs, hookers, porn movies, etc. Fran is persuaded to leave Remick, but, knowing that he will come after her, Cass has her hidden away in a country location. In a staged robbery-gone-wrong, she is later shot dead.
Cass knows that Remick is behind the killing. Setting about gathering proof, he discovers photos left for him by Fran which tie Remick to a snuff movie in which another girl, Libby, is brutally murdered; he then uncovers a blackmail plot in which Remick plans to extort millions from the playboy heir to a fortune by implicating him in Libby’s murder.
As Cass tries to tie all the strands together he receives out of the blue a videotape that confirms Remick’s guilt and will wreck his blackmail plot. He also learns that Libby’s father, Frank, is on the hunt for Remick, vowing payback for his daughter’s killing.
The story ends in a bloody denoument involving Cass and Remick’s crew, and then Frank and then Remick himself.