Murder mystery novels have entertained readers for centuries and, over the years, certain conventions common to murder mystery plots have developed. These conventions help authors build intriguing characters and riveting murder mysteries. The authors create a puzzle that the reader is compelled to solve, and earn loyal fans in the process.
The murder is the central plot in any murder mystery. It might occur before the book begins, but most often the reader witnesses it near the beginning of the book. The murder creates a crime scene where the murderer hopefully leaves enough evidence to aid the detective in his inquiry. The rest of the book centers on finding out who killed the victim, how he killed him and why.
Even though the author doesn't reveal the murderer until the end of the book, the murderer is an important character. He should be someone whom the reader has gotten to know throughout the course of the story, but does not readily suspect. The reader should be surprised when she finds out the murderer's identity, yet the revelation of the villain should make sense upon reviewing the clues.
The victim often dies near the beginning of the novel, and the reader gets to know him through flashbacks or through the testimony of neighbors or friends. It is important for both the reader and the detective to learn as much as possible about the victim because this is often the key to the motive for killing him. The motive often leads to the capture of the murderer.
Many murder mysteries feature a private detective or an amateur detective who has a colorful personality. He frequently appears in a series as a recurring character. Agatha Christie's Hercule Poirot and Ms. Marple or Conan Doyle's Sherlock Holmes fall into this category. Readers identify with amateur sleuths because they like the idea of an ordinary person solving a crime. However, the author must create a compelling reason for an amateur to be involved in a murder investigation; otherwise, the amateur's involvement might seem unrealistic.
A murder mystery must have clues that aid the detective and the reader in solving the case. The skilled mystery author also plants red herrings. The name comes from an old practice of using a type of fish called red herring to distract hunting dogs from the scent they were tracking. In a murder mystery, a red herring appears to be a clue, but instead sends the detective in the wrong direction. The detective obtains clues from the crime scene, the murder weapon, the victim and from witnesses. The author should reveal all clues to avoid having the reader feel cheated.
Misdirection and Twists
Most readers of mystery novels expect one or more twists. Twists can involve almost any aspect of the story. The murder weapon might turn out to not be the real murder weapon. Someone might confess to a crime even though he didn't really do it. The most common twist normally occurs at the end, when the last person the reader expects turns out to be the murderer.