One of the most popular sub-genres of detective fiction, the locked room mystery, takes place in a situation where it would seem to be impossible for somebody to commit the crime. The most popular example being a dead body found in a room, locked from the inside. Several possibilities about how the victim was killed must be eliminated, including the use of poison, trap doors leading into the room, the person committing suicide and the killer setting up any device to eliminate them.
To qualify as a locked room mystery, the murder must appear to have been executed behind closed doors by an unknown suspect. The killer also disappears in a way that defies logic, appearing to have simply vanished into thin air. Readers are normally presented with the crime, and the clues, and challenged to solve the mystery. As with most detective fiction, there is always an unexpected twist at the end of the story. Most other novels in the detective fiction genre, place their focus on the ‘whodunit,’ while locked-room mysteries must first determine the ‘howdunit.’
A History of the Locked Room Mystery
The inspiration behind locked room mysteries goes back thousands of years, and includes the biblical story of Bel and the Dragon. Many people were worshiping an idol that was locked in a room, and would reportedly eat offerings left for it here. The hero, Daniel, proved that the idol was a false god by revealing the existence of a secret entrance into the room.
The origin of the sub-genre, however, is credited to 19th century authors, such as Edgar Allan Poe who wrote The Murders in the Rue Morgue in 1841. The key feature of the locked room mystery expanded to include ‘misdirection,’ after Israel Zangwill published The Big Bow Mystery in 1892. During the same era, Sherlock Holmes became the leading detective in locked room mysteries, cementing the sub-genre in readers’ hearts forever.
In the Golden Age of detective fiction, many popular authors experimented with locked room mystery stories, such as Agatha Christie. There were other writers that specialized in the sub-genre, including John Dickson Carr (Carter Dickson), who created some of the most intriguing locked room mysteries to date. Stories in the sub-genre appealed not only to English-speaking audiences, but also flourished in France and Japan. These countries continued to enjoy their mystique, after WWII caused a decline in its popularity in Britain.
Locked room mysteries began to regain their popularity in the 1970s, and their publication continues to fluctuate. There are many written specifically for younger audiences, where the crimes are not as gruesome as murder. Enid Blyton has been one of the most prolific authors of these, and helped develop greater cognitive abilities in a generation of children.
The sub-genre has also been adapted for the film and television industry. Many books have been turned into films, including Sherlock Holmes episodes.
True Locked Room Mysteries
Many people think that locked room mysteries only happen in fiction. Whether inspired by books, or their warped imaginations, there have been real killers that bring these stories to life.
- The Laundry Killer
On March 9, 1929, Isidore Fink was locked in his laundry on 5th Avenue, New York. A neighbor heard screams and the sound of blows coming from the shop, and called the police. When the authorities arrived, they were unable to enter the building and lifted a young boy through the transom. The child could not unlock the door, but observed the owner lying on the floor dead. Mr. Fink had received three shots: two to the chest, and one to the wrist. There was no weapon left at the scene, and the money in the cash register had not been touched.
Detectives speculated about the possible method the killer used to enter and leave the scene, including the fact that they had also used the transom. This meant they would have had to be the same size as a young child. After two years, the case remained opened and was referred as an ‘insoluble mystery’ by the Commissioner of Police.
- Paris Metro First Class Murderer
On May 16, 1937, a passenger was found stabbed in an otherwise empty first class compartment, on the Paris Metro. During the 1 minute and 20 seconds it had taken the train to travel from one station to the next, Laetitia Toureaux had been killed, and the murderer had vanished. Authorities have never been able to determine who the killer was, or how they had escaped.
Solving a Locked Room Mystery
One of the most satisfying things for a reader is to solve the mystery correctly, before the author reveals the twist at the end. Writers follow certain guidelines when developing their story, which can provide clues to the killer’s identity. These include:
- Work your way from the end to the beginning – Locked room mystery authors often write from the ‘back to the front’ meaning that some of the most essential clues are provided at the end of the novel. If readers follow this sequence, they may be able to pick up on carefully disguised components needed to determine the who, how and why of the plot. This method can be compared to working a puzzle out by doing the edges first, and then filling in the pieces on the inside.
- Pay close attention to deception – In a locked room mystery, everybody becomes a suspect. Never forget that! Often the person who seems to be the least likely to have committed the murder, is the one who has done it.
- The author provides everything that is needed to be able to solve the mystery – A good writer will never short change their reader, but will try to disguise the clues along the way. This means that the audience will always be provided with everything that is needed to get to the bottom of the mystery.