Are you writing a murder mystery novel and looking for tips on how to write a whodunit story? We’ve include 10 below to help make your book a scintillating one!
1. Start your story with the crime and end with the reveal.
Why it helps:
Mystery stories like Whodunits are popular entirely because readers get to feel like they are figuring out the mystery along with the detective in the book. For readers to do this, they need to see the crime early on, so they can spend the rest of the book trying to solve it. They also need time and clues to discover along with the detective, so revealing the crime too early would make the rest of the book seem pointless.
How to use it:
Try to reveal the crime no later than the third chapter. You can spend the first two chapters introducing the detective and a bit of their backstory. You want the bulk of your narrative to be between the crime and the reveal, so try to make the reveal as close to the final chapter as possible. You also don’t want too much epilogue as the point of a whodunit is to figure out the perpetrator and move on to the next mystery to be solved.
2. Plan the plot backwards.
Why it helps:
The ending of a mystery story is the detective explaining how the beginning came to be. Planning the story in reverse ensures that all the clues the detective discovers are connected to one another and related to the crime.
How to use it:
Write out the solution that your detective will give at the end of the story. Include all the clues and connections the detective will need to discover who the right suspect will be. Then, work backward to show how the detective found those clues.
Finally, end with deciding which clues will be readily available in the crime scene and which clues will need to be discovered because the detective did some investigating. This should lead to a description of the crime scene as it is at the start of the book.
3. Introduce the reader to the perpetrator early on (without revealing they committed the crime).
Why it helps:
Statistics don’t lie: most crimes are committed by those people close to the victim. Readers know this statistic, too, and will immediately begin looking at the characters you introduce early on that are connected to the victim. This is so they can match clues and motives to characters in an effort to ‘figure out the mystery’ before your detective does.
How to use it:
Introduce an ensemble of suspects early on. This could be through their physical proximity to the victim (such as in every Agatha Christie novel) or because they have something to gain from the victim’s death or disappearance (such as in pulp detective novels like The Maltese Falcon or The Big Sleep). This will give the readers people to consider as they read and make for good suspense.
4. Create a believable setting for the crime.
Why it helps:
Every crime has a crime scene: it’s the place the crime either took place or where the victim was discovered (as those aren’t always the same). Most of the clues will come from the crime scene, so they need to be described as fully as possible for the reader to pick up on the same clues the detective will.
Overly complicated settings (and, by extension, crimes) will confuse the readers and lead to your detective making leaps in judgement that readers may not understand or support, which will make them not enjoy the story as much.
How to use it:
If you plan your plot backward, then you should know exactly which clues need to be readily available from the start. The crime scene should be a place that has some connection to the victim (their office, home, car, etc.). Or, if the victim would never be in this place, then that needs to be glaringly obvious to begin with, as a clue for the detective to follow.
Be sure that the perpetrator wouldn’t have to jump through hoops to create this crime scene. This is so that, when the reveal happens, the reader has the same ‘Aha!’ moment the detective did.
5. Give your main characters interesting backstories.
Why it helps:
Readers are more likely to become invested in your story if the three main characters—victim, perpetrator, detective—have interesting reasons for being there. The detective, as the main protagonist, needs to be interesting enough for the reader to want to root for and follow as they discover clues.
The victim needs to either be a decent person that needs justice, or so horrible that the reader wants to find out who should be celebrated for hurting them.
The perpetrator should also be either an absolutely horrible person (to justify being arrested for their crimes) or a decent person who’s been wronged (to justify committing the crime).
How to use it:
When planning the crime, be sure to create a motive and method that matches the characters themselves. Be sure to answer questions like: Why does this victim have a crime committed against them? Why does this perpetrator do it? Why does the detective feel a need to solve this crime (apart from professional duty)? These are the answers that will make your crime story different and more engaging for the reader than other stories.
6. Include a couple of believable red herrings.
Why it helps:
Red herrings (or plausible misdirections) are a natural part of problem solving and discovery. If your whodunit didn’t have any red herrings, the reader would find it unbelievable. Your readers will make mistakes in interpretation while they’re reading, so your detective should do it, too.
At the same time, be sure not to overwhelm the reader with too many clues and red herrings. That would make the crime too easy or too overwhelming to solve, and your reader would lose interest quickly.
How to use it:
When writing out the list of clues that the detective will use to solve the crime, include a couple of clues that will lead them to the wrong suspect or wrong motive. Have your detective follow them for a chapter or two but be sure to show how the detective discovers they were on the wrong track. Maybe it’s a new clue or maybe they challenge the wrong suspect only for that person to say something that leads them back on the right track again.
7. Ensure the crime scene and backstory leading to the crime is believable.
Why it helps:
Readers of whodunit mysteries want to be able to discover the motive and method of the crime before the detective. However, that doesn’t mean the crime should be so simple that the reader guesses who committed it, and how, before the first clues are discovered.
How to use it:
When imagining the crime, don’t overcomplicate it. Be sure that you could explain, in one simple paragraph, how your perpetrator executed the crime and why they got away with it (at first). Think about how there may have been strokes of luck (someone just missing them in an elevator or not looking up in time) which allowed them to avoid detection early on.
When describing the crime in the story, include only those elements seen at first glance. You want your detective, and your readers, to look ‘between the lines’ to find the clues that will ultimately lead to more clues and speculation.
8. Never make the detective the perpetrator.
Why it helps:
While it might seem clever, it’s considered an amateurish trick. It makes the reader feel fooled and short-changed as nobody would ever guess the detective themselves to be the antagonist. Some mystery stories have successfully had the victim be the perpetrator (think: Gone Girl), but never the detective. This is because it would result in the story itself being meaningless as there would be no point in the detective unearthing their own clues.
How to use it:
The detective shouldn’t know or be connected to the victim in any way. This will make sure that there is no possibility of the detective becoming the perpetrator. Easy ways to do this is to have the detective be a ‘professional’ detective, either with the local police or as a private investigator, who is hired by the victim’s family and loved ones. This will make that disconnect for the reader early on.
9. Don’t include anything that’s considered a ‘cheat.’
Why it helps:
Just like with the previous tip, cheating the reader is a big no-no and will isolate your audience. So, avoid any plot devices like the supernatural, the use of doubles/twins, accidental discoveries, or someone coming in at the end to ‘save’ the detective. Readers read whodunits so that they can feel as clever, if not more, than the detective in your novel. If you include surprises, then you rob the reader of that feeling of accomplishment.
How to use it:
This isn’t to say you should never use doubles or the supernatural. You should just be sure they aren’t surprises for the reader. You can avoid this during the planning of the crime and the clues you’ll include. Just make sure there is nothing which requires a massive leap in consideration or judgement.
If you do use doubles, then you need to give hints throughout that suggest the person they’re seeing is not the same person they were introduced to early on. If you want to include the supernatural (or subvert that, as done in the Sherlock Holmes’ story The Hound of the Baskervilles), then you need to have a supernatural element from the beginning and establish the ‘rules’ of the supernatural at the start, so the reader knows what to expect.
10. If you do want to do something different, make sure it’s believable.
Why it helps:
There are lots of mystery writers who don’t ‘follow the rules,’ but they always make sure the rules they break are believable. Think of a film like The Usual Suspects: Kaiser Sose ends up being the last person the viewer would expect but, upon rewatching the film, all the clues which support that final reveal are there.
How to use it:
If you want to do a twist ending, be sure you have laid the relevant clues supporting that ending throughout the story. You want your reader to be surprised but also able to review the clues you’ve given to show how they match up.
A good way to do this is to lay out each step and stage of the murder then create a clue (or three) that match to more than one of your characters. These aren’t red herrings, per se, as you won’t direct the reader to those other characters. You will simply not direct them to the actual perpetrator, leaving them to never suspect that person until the detective announces who it is and how they did it.