A 4-Step Guide to Writing a Murder Mystery

April 8, 2024

Crafting a murder mystery for the first time is like learning the violin.


After listening to a compelling performance on Youtube, a burst of excitement overwhelms you. You’re sure that, with minimal practice, you can master the instrument too. So you hop onto Amazon, scroll through a few reviews, and buy a set of strings and a bow. Thus armed, you attend your first lesson.


Your confidence then explodes. The teacher talks about shoulder rests and resin, frogs and violas, tuning pegs and horse-hair bows. With sinking dread, you realize that becoming a violinist is far more complicated than you expected, and playing that song from Youtube may take years.


Admiring an artist’s technique is one thing, and trying to replicate it is another. No matter how many capers you’ve binged, you still need specific instruction on how to interconnect all the pieces. Meticulous plotting (which readers can’t see) contributes to the thrill of the sleuth catching the villain. Although a single article can’t cover all the nuances, four basic principles govern the genre.


1. An Invested Protagonist

The police have drawn a chalk outline around a fresh corpse, and you need to lead readers to the culprit. Planting clues is harder written than said, however. Getting the timing right can be tricky, and the ending should be unpredictable yet, in retrospect, look inevitable. You have to discern when to drop a clue into the protagonist’s lap and when to make her search for it. But before any clues can be discovered (or gifted), she must have a reason to care about solving the case.


Many mysteries feature detectives whose primary incentive is to avoid boredom, such as Sherlock Holmes and Hercule Poirot. Others have a more personal connection to the crime. In The Seven and a Half Deaths of Evelyn Hardcastle, the protagonist is trapped inside a simulation and will continue to experience the same day over and over until he identifies the murderer. In Richard Osman’s The Man Who Died Twice, the victim is a central character’s ex-husband. Both are close enough to home to propel the characters through the ups and downs of the investigation.


To ensure your character’s motivation is strong enough, prevent her from returning to normalcy. In Knives Out, an anonymous person hires an obsessive detective who can’t rest until he’s tied up every loose thread. In the ABC Murders, Hercule Poirot receives taunting letters and deduces that the butchery will keep occurring unless he outsmarts the sender. Furthermore, his reputation as a peerless detective might suffer.


If your protagonist is devoted to the chase because the police are inept, beware that this trope is flimsy and overused. Your story world’s justice system may have flaws, but too much incompetence can seem like a lazy attempt to impair the competition and empower your protagonist. So be clever about how you represent less-than-capable law enforcement. Corruption, for example, is more believable and easier to twist to your story’s needs.


You’ll want to solidify your protagonist’s motivation around the 25 percent mark, which will provide the momentum for her to pursue her opponent during the remaining 75 percent. A series of revelations about the murderer will gradually escalate this game of cat and mouse.    


2. A Villain with a Vendetta

Every story starts with a disruption that’s distinct to the genre. In classic fantasy, it’s a (probably grumpy) wizard. In romance, it’s the flutter of attraction. And in a murder mystery, it’s death. But for the question of “Whodunit?” to hold any tension, the perpetrator, like the protagonist, needs a goal. His rationale will determine the clues he leaves behind—and, by extension, the direction the protagonist will go.


For instance, let’s say the killer is an inventor who is stealing the credit for a highly profitable machine. He systematically terminates anyone who knows he didn’t build it so he doesn’t lose the wealth he’s accumulated. After analyzing the string of murders, the detective might notice that all the victims were involved in the same project ten years ago. He might interview the still-alive inventors, eavesdrop on the facility’s other employees, or research the prototypes that failed and why.


The method and setting of the murders can also influence where a trail appears. In the first episode of BBC’s Sherlock, the murderer is a cab driver who accepts money to become a hitman for an incognito passenger. Because of his profession, one of his tells is the fact that he abducts his victims from crowded places to avoid detection. One woman forgets her phone on the backseat, and Sherlock uses it to track the cab driver down.


3. Evolving Evidence

After you’ve planned out the murder, the next phase is more flexible. How the protagonist gathers information will be unique to her personality and situation. Some detectives interrogate witnesses, some examine crime scenes for overlooked details, and some explore the past. The only requirement is that the source is linked to the murder.


Depending on the character arc you’re aiming for, splitting your novel into two sections may make the process less intimidating. The first half will generally revolve around your villain’s actions while the second half will revolve around your protagonist’s actions. The investigation is ongoing during both, but how the protagonist responds will change. Initially all she’ll see is a collection of unrelated deaths. But by the midpoint she’ll possess vital intel that explains (and predicts!) the pattern of murders.


In Knives Out, Marta struggles to stay ahead of the detective, who gets closer and closer to figuring out that she accidentally fed her patient a fatal dose of morphine instead of his nightly medicine. In the ABC Murders, the hero receives three letters, each punctuated by a new murder, with no recourse except to grill the survivors. In contrast, the second half of each of these stories is marked by the heroes applying their findings to nab the culprit.


Remember, although the protagonist begins working independently of the villain, he won’t cease his killing spree. Usually he’ll retaliate before the climax, a sign that the protagonist is gaining on him. However, even if he doesn’t harm anyone else, she’ll be able to move forward without waiting for a cue from him.


4. Fascinating Reveals

As your protagonist forms theories about the murderer, your scenes can quickly become redundant: interview a suspect, get a lead, follow it, and repeat. Since conversations tend to dominate most mystery novels, the interactions must feel fluid and natural rather than contrived. One of the most effective ways to curb this problem is to show, not tell—especially characters’ motives and flaws.                


In Knives Out, Detective Benoit spends a lengthy amount of time asking for the characters’ opinions of the dead man. They lie and backstab each other, but between each snippet of dialogue is a flashback covering what really happened. The dead man informs all the children that he’s removing his financial support. And Marta’s relationship with her mother and sister demonstrates that she’s hiding her mistake for the sake of her family.


Instead of having your protagonist confront all of the suspects, let him observe them. Suspect number one is protective of his little sister, who the murdered man pressured to marry him. The wife whispers to the family butler, who she’s rumored to be having an affair with. Visual portrayals offer readers the satisfaction of drawing conclusions themselves.


As Easy as G-D-A-E

You’re clutching your violin bow with your pinky on top and your thumb tucked just so. You’ve run the horsehair over some rosin and tuned your strings. Now you feel like a real prodigy.


But knowledge is only half the equation. A song requires practice to be beautiful, and a mystery novel requires revisions to be perfected. Don’t be discouraged if beta readers recognize the killer too soon, or when you realize that the villain couldn’t have slipped in and out of a locked room. If you could ask Agatha Christie how long she wrote before fans crowned her the Queen of Mystery, I’m pretty sure she’d have to count in years. Point is, if you persevere, you’ll have readers gripping the edges of their seats.

1 Comment

  1. E. C.

    This almost makes me want to write my own murder mystery. 😂
    These pointers are so helpful though, even in the mystery subplot in my WIP. 🙂


Submit a Comment

Your email address will not be published.

Article Categories

Pin It on Pinterest