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Locked Room Crimes

By Wm. Garret Cothran


Crime is fun.


Some will disagree but, in all honesty, people love crime. White collar or blue collar. Serial killers or a guy who snapped.


Bank robbers. Bandits. Mafia dons and Yakuza bosses. Crime is fun and exciting.


While for Alternate History, crime offers a fine window into a world from time to time, a writer tends to treat crime as nothing more then a means to an end. Yet as some great crime authors learned, there are standards and rules for making a crime which the readers will enjoy. In this matter we will be looking into what is known as a locked room mystery.

What is a locked room mystery?


Well, unsurprisingly, it is a mystery surrounding a locked room. A more in-depth definition requires only a couple more elements: a murder, and the murder occurring in a place people cannot easily reach. Some will say it can be any crime which is “impossible” but more often then not, it is a murder.

Byam Shaw's illustration for Poe's The Murders in the Rue Morgue in "Selected Tales of Mystery" (London : Sidgwick & Jackson, 1909) on the page to face p. 284 with caption "The sailor's face flushed up; he started to his feet and grasped his cudgel"

As long as folks have been writing murder mysteries there has been someone writing about a locked room murder. The first real modern example was Edgar Alan Poe and his French detective C. Auguste Dupin in The Murders in the Rue Morgue. For those unfamiliar with the story, a brutal double murder occurs which began in a locked room on the fourth floor of building.


The answer is (and sorry, but the book is from 1841 so spoilers seem a tad moot) a trained orangutan was doing the murders.


Yep… the first real modern detective story was about a trained monkey killing folks. Next time you eye-roll at Midsommer Murders or Elementary or whatever is on at 8 o’clock on a Thursday, try to recall it all began with a pet ape trying to learn to shave.

As time went on more and more such stories were written. G.K. Chesterton’s Father Brown had numerous locked room mysteries. Stories from Agatha Christie’s Hercule Poirot to John Dickson Carr’s (a prolific writer in the Golden Age of Mystery Novels) Dr. Fell to even more modern tales like Japanese Mystery author Soji Shimada’s The Tokyo Zodiac Murders. The BBC, or if one is an American, PBS’s Masterpiece Mysteries, is full of such murders and all manner of refined or bumbling, or finicky detectives moving about. All of this allows a writer to enjoy a wealth of information if one needs it to craft your own locked room murder. Yet what are the rules for such a thing?

The man to look for a solid way to view such crimes, from a literary standpoint, is one Dashiell Hammett. Before getting into his views on how to write “a murder in a locked room”, as written in Selected Letters of Dashiell Hammett, one needs to understand what a fascinating fellow Hammett was.


As a young man in 1913 he joined the Pinkerton Detective Agency and worked as a strike breaker, before joining the Army in WWI. Hammett spent all of WWI in the hospital having become ill with the Spanish Flu and then, if that was not bad enough, came down with the start of his life-time infliction of tuberculosis.


After the war he moved to San Francisco and began his writing career.


It is in this period that Hammett began his career in left wing politics. In 1937, he joined the Communist Party after almost a decade of a staunch anti-fascist stance. In Continental Op, a series which Hammett wrote from 1923 to 1930, the lead character (the unnamed Continental Operative) often would speak ill of Mussolini. While to modern readers, someone speaking ill of Il Duce is hardly surprisingly, for the time period it was far from common amongst US writers and authors. As with many Communists in the late 30’s, Hammett is not free from guilt: he openly called for US isolationism during the Molotov-Ribbentrop Pact, only to quickly change course following the German invasion of the USSR.


In World War II Hammett reenlisted (which is saying something for a disabled WWI veteran who was a Communist and had tuberculosis) only to serve in the Aleutian Islands and work on an Army Newspaper. It was on these islands that Hammett developed emphysema. Sadly, post-war Hammett fell victim to MacCarthyism, and was sent to prison for contempt of court. Out of prison, Hammett was blacklisted and from 1953 the man just slowly withered away until his death in 1961.

By now one would be asking: why in this discussion on Locked-Room Mysteries is so much time spent discussing the life of a single author?

Well, that is mostly because Hammett is credited for creating numerous mystery archetypes in the detective and mystery genre.


Maltese Falcon and The Thin Man series are known throughout the world: both were written, both in novel and screenplay format, by Dashiell Hammett.


The man wrote Nick and Nora Charles and Sam Spade. He is seemingly the man who created that hard-boiled noir detective, as well as the witty bantering husband and wife detective duo. Yet in public, this man was a communist. Not just some fellow who liked left-leaning politics - a card carrying, fully blacklisted communist writer.


What is important in this, is that Hammett wrote specific rules for a locked room mystery and one of them was “always write about crimes that require a reservation.”

That means that to enjoy the suspense of a locked room mystery you need to enjoy a level of wealth. At least when it comes to the lock on the door. Poverty invokes images of disrepair and poor craftsmanship. It is easy for a reader to envision breaking down a door or rummaging about a poor man’s home then it is to do such things with ease in a rich man’s. Now, not all need to follow this idea of Hammett’s, but there is some validity to the central idea that the crime has to occur in a place the reader can believe the location is secure. This can either be in the detail given to the room itself by the author, or the general atmosphere and tone.


This gets into other ideas like “higher the crime the better.” Hammett felt that a proper lock room mystery had to occur on anything above the second storey, and in a room with either no windows, or windows set against a sheer wall. The door is not an unbreakable fortress but it is strong and sturdy. Any author working on such a murder needs to take the time to map out not the crime but where the crime occurs.

Once the location is selected, and you can map out the hallway, rooms, and more what follows is more of a style choice. To Hammett a murder is solved in one of five ways:

1) The reader has the facts. So upon finishing the murder, and reading over the details given, a reader should in theory be able to figure out the crime on their own. This is viewed as one of the hardest ways to write a locked room mystery, or in fact any crime. While it may hold allure to writers as a challenge it requires one to almost plan out a murder in full just to ensure all the details are present.


Alongside the secrets and twists and turns, any good mystery needs (if one writes with the intention the reader should figure out who the culprit is), by the very end of the murder, to have presented the reader with all information needed to point to who did it. To Hammett, while this style will win one acclaim from fellow mystery authors, he did warn that “in the end being clever just makes an editor scratch his head and wonder why so much detail was put into explaining how a pocket watch had a secret compartment.”

Think of a room. A study. No windows. One door. The man is dead over his desk. A key in his pocket.


The wife of the man went upstairs to the sound of the butler shaking and pounding on the door. It will not open - no matter how hard the butler shakes the door.


He breaks it down. The man is dead. Knife in his back. Body is cold. The butler delivered tea to the man while the wife was collecting some papers. Everyone knows the crime had to occur in the last hour - when the butler and the wife had an alibi. Someone tried to call but the phone line was busy. The phone was on the hook so the man was killed after the calls.


Did you figure out the crime? If you did, good for you. If you did not, that is why Hammett views this as such a difficult method of showing a locked room mystery.

(In case one is curious: the butler did it. He stabbed the man and took the phone off the hook knowing someone would call in ten minutes. After setting up an alibi, the butler later just pretended the door was locked, entered hung up the phone while everyone focused on the body.)

2) The detective has the facts. This is what is most familiar to various readers and fans of mystery novels, films, or television. It is that one scene when the detective gathers everyone up in the parlor and explains in detail: not only how the crime occurred but who, present in the room, is in fact the killer.


This is seemingly Hammett's preferred manner of solving a case. Not because the reader is too dumb to figure out something but because “it places at the core, the character.” The way the “parlor scene” unfolds is as telling of the detective in the novel, as it is of the story itself.


Adrian Monk would “here’s what happened...” his way into a flash back. Nick and Nora Charles always seemed to host a nice dinner party and act as perfect (albeit rather drunk) hosts before Nick Charles pointed the finger at “the real killer.” Think of any famous literary detective and there is a very clear style as to how they explain the crime.

For a locked room mystery this is perhaps the easiest thing a writer can do. It invokes a level of deus ex machina to some, however. Hammett felt that while one could in effect make up anything in the last five pages to explain the murder, this was fine so long as the way this played out was consistent with both the main characters and the overall tone of the story.

3) A key piece of evidence is found showing the facts.

Here it is more like a smoking gun.



There is a random seemingly useless trinket that holds greater significance. For Hammett, nothing shows this off better then Maltese Falcon, even if in that particular story it was a red herring.


That item or trinket which is of such importance someone would kill over it. In effect giving way to how a crime was committed.

In Silent Speaker author Rex Stout had Nero Wolfe (imagine Sherlock weighing 400 pounds, refusing to leave his home, and refusing to change his schedule of eating, reading, and orchid raising for anything) learn of a murder in his very own home. Yet the detective focused not on how the crime occurred but more on what was being hidden.


Which was simply a recording of a man explaining a crime. Yet this recording is important as Wolfe would stress “it was not she was strangled in my home, but why she was on her knees facing a bookshelf with no signs of struggle.”

While similar to the first point in that the reader has information needed to solve the case themselves, it combines more of the second part, in that it allows a reader to get a glimpse into how the detective’s brain works.


Hammett really enjoyed this particular method. Such as Thin Man’s Nick Charles going to a Chinese restaurant and playing dumb just to get to hear rumors about someone only to spot a matchbook that - from his angle - looked exactly like the mark the victim left in his room. Hammett’s Sam Spade and Raymond Chandler’s Philip Marlowe would pound the pavement and speak to specific people - which, only at the end, lets the reader see all that is connected thanks to the mind of the detective.

For a locked room mystery evidence tends to be the how the room was locked. This, to Hammett, was the key to telling the story. For it was not merely that a criminal was clever and effective, but the criminal was so clever, you need to view things from a specific angle just to even attempt to solve the case.

This method tends to have more favor as it gives the illusion to a reader that they are discovering clues as the detective does, but also allows for the parlor scene style ending in which all clues are laid out and explained in full. Unlike in the second method, where it all remains hidden by the detective until the last moment, it is open and easily seen by the reader. For it is better for someone to think they could have figured it out then for them to know just how “dull and dim” they really are.

4) The killer has the facts. This is something which Hammett attempted but, in his view, “never was able to pull it off.”


The main focus here is flipping the story on its head. This is not that the killer knows everything but the story is openly showing the reader how the impossible murder occurred. So it is placing the killer as the protagonist and the detective as the antagonist.


The best example for this the American television show Columbo. It is about Lt. Columbo, a dirty looking, cigar smoking, bumbling kind of fellow. Yet every single episode begins with the criminal planning, enacting, and seemingly getting away with murder. If one has not seen Columbo, give it a watch. It shows this concept in full with the audience able to know how the crime occurred, all the tiny little details, and even how it appears like the criminal got away with it. Of course, Columbo solves the case every single time but the build up to this may be a good tool for aspiring writers in trying to figure out how a crime would occur.

Look up where special guest star Dick van Dyke is the murderer in Columbo. It is fantastic from a narrative perspective.

5) The body has the facts. In 1939 Hammett read And then there were none (then known as Ten little N**gers in its original more offensive title) by Agatha Christie.

The man loved the book. While he framed it as a fine example of elitism and oppression upon the people (as these were his more active communist days), he still found it the most “impossible murder ever put to page.” To explain the twist is to spoil the story so fair warning.

This method explains things as the impossible action is done not by a third party, but the victim themselves. We all have seen a story or two in which the victim is killed in a seemingly fantastical fashion only to learn it was an elaborate suicide. In And then there were none, a man with a terminal illness decided to engage in the bloodlust he had denied himself for so long. After some effort he not only kills everyone but he kills himself as well. The only reason the reader knows the secret is the killer's confession at the end of the book.

This particular style allows for an easy twist ending but also for showing flaws in the detective or the views of others. We as people, all the more so as readers, expect a logical and clear narrative to crime. One man did it, here is how he did it, and now he goes to jail. This particular style of a locked room mystery to Hammett held “the infinite potential” to show all the flaws in mystery novels while also itself making a good mystery.

Now with all of this done, what on earth does this have to do with Alternate History?


As discussed previously, crime is an easy and quick way to dive deep into a story, while focusing on crime allows one to explain long distance travel, dealing with various socio-economic groups, as well as explaining changes to a society big and small.


A locked room mystery, from a writer's stand-point, offers up something unique to both the creators and readers of such works. Namely that you can delve into lives of people and do so without it being expositional or seemingly pointless banter.


Do not think pointless banter is always bad, mind you. Some of the best detectives in fiction do nothing but pointless banter and we love them for it. Yet a locked room mystery gives a writer the freedom to go anywhere and do anything while staying inside the narrative of the story. A trip to a King or a powerful corporate CEO or some board guard in a dusty town is not just something forced upon the reader if the crime being investigated leads one there.

Crime always will be a fine window into any society, yet, as some mystery writers found, the hardest thing is not the story but finding a crime that fits the story one is writing. The locked room murder offers up numerous options to authors, but moreover allows one to tie in all manner of people, places, and personalities without even having the characters leave the same building.

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Wm. Garrett Cothran is the author of How Tall Is The Grass In Germany? published by Sea Lion Press