Crime Fiction Sub-Genre Distinctions (an encore)~Plus a New Contest!

by Kassandra Lamb ~ In April of last year, I wrote this post about the distinctions between some of the mystery sub-genres. I’m re-running this post (with a few tweaks) as the introduction to some other posts coming up, that will hopefully further clarify certain crime fiction sub-genre distinctions.

Crime Fiction Sub-Genre Distinctions That Are Clear As Mud

Genre definitions and crime fiction sub-genres can be quite murky and confusing for both writers and readers.

First there is the question of what is crime fiction. Some use it as a broader umbrella that includes any kind of fiction related to crime (including true crime, which isn’t fiction) and view mystery as one of its main sub-genres. Others use the two terms interchangeably (as we do here at misterio press).

If you do a search for mystery sub-genres, you will find lists of anywhere from 4 to 22. Some lists include thrillers, others view thrillers as a separate genre. Also, one will find somewhat different definitions of these genres and sub-genres.

And some stories have elements of more than one, so where do you put them?

Below are 3 distinctions between crime fiction sub-genres that can be pretty fuzzy. I will attempt to clarify, but I should note that these definitions are based on my understanding of the genre.

Is it a Thriller or a Mystery?

Here is the clearest distinction I’ve ever heard (not mine originally, I learned it in a workshop at a writers’ conference):

  • In a mystery, something bad has already happened and the protagonist is trying to figure out who did the bad thing.
  • In a thriller, something bad is going to happen and the protagonist is trying to figure out how to stop it from happening.
crime fiction sub-genre distinctions ~ thrillers
The only true thriller I’ve written, so far, complete with a ticking clock.

Thrillers are usually fast-paced. But pacing, in and of itself, does not turn a mystery into a thriller. A very fast-paced mystery should probably be called “suspense.”

Thrillers often have higher, more global stakes, such as the destruction of the world, the assassination of an important leader, etc. But the stakes may be more narrow, such as a serial killer targeting a certain person and the protagonist must stop them before that person is killed. Or in the case of a psychological thriller, the stakes are often one person’s sanity.

In a thriller, the reader may very well learn early on the identity of the bad guy(s)/gal(s)… or at least gets some insight into the antagonist(s), maybe even via scenes from their point of view. But this can happen in a mystery as well.

The key differences

These are the timing of the bad event (past or future) and the main goal of the protagonist (solve the crime or stop the bad event from happening).

But then there is the story where a bad thing happens and the protagonist is trying to solve that crime, and then another bad thing happens, and another…and it becomes apparent that even badder things are coming unless the protagonist can figure it all out pretty quick.

crime fiction sub-genre distinctions ~ is it mystery or thriller
Sasscer Hill’s The Seahorse Trade shifts toward thriller when Nikki Latrelle suspects a missing girl has been taken by sex traffickers.

Is that a mystery or a thriller?

Good question. The answer is… it depends.

And that is when these other elements may swing the decision one way or the other.

If there’s been a murder, and then there are other murders, but they seem to be related to the first one—as in the killer is taking out people who might be able to incriminate him/her—and the stakes regarding the future bad thing are more narrow—as in someone near and dear to the protagonist is going to be the next victim—then it’s probably a mystery.

If a crime has happened and as the protagonist gathers clues and more crimes accumulate, it starts to look like a bad thing is going to happen that has much broader consequences, then it might very well be a thriller—especially if it’s fast-paced and the reader is given glimpses into the antagonist’s world.

Is it a Traditional Whodunit or a Cozy?

crime fiction sub-genre distinctions -- traditional
Book 1 in my traditional series.

Some people use these terms interchangeably, but my understanding of a traditional mystery is that it is similar to the more classic stories from the early years of crime fiction, ala Sherlock Holmes and Agatha Christie’s Murder on the Orient Express. (Some consider these stories a sub-genre in their own right, the Golden Age mysteries.)

Today, traditional and cozy mysteries both have amateur sleuths, and while gore, on-screen sex, and swearing are avoided in both, some of all of the above is allowed in traditional if it serves the story.

In cozies, those three things are pretty much forbidden. And usually the stories are set in a smaller community, such as a small town. Often the protagonist has a particular kind of vocation or avocation—bookstore owner, crafter, antiques dealer, etc. Animals are often involved as well.

Cozies also tend to be lighter, perhaps less complicated, stories than traditional or other kinds of mysteries.

But I can tell you, after having written a 10-book traditional series and now working on Book 13 in a cozy series, it can be really hard to tell where the line in between rests sometimes.

crime fiction sub-genre distinctions -- cozies
The first book in Shannon’s cozy series.

Maybe that’s why I’ve decided that my next series will be a police procedural…LOL

Is it a Cozy or a Caper?

Capers are another lighthearted sub-genre, or at least they’re usually lighthearted. Some people even consider them a sub-genre of cozies.

But they aren’t always light and fluffy. The movie, Thelma and Louise comes to mind, which was lighthearted in places, but definitely not at the end.

The distinguishing characteristic of a caper is that it is written more from the criminals’ perspective. In the lighthearted ones, the bad guys/gals are often kind of inept, leading to humorous mishaps along the way. The TV show, Good Girls is a great example.

But there are plenty of other capers that focus on quite skillful criminals. They may very well have plenty of humor in them as well, but the mystery is in whether or not they will pull the crime off, and if so how.

There are also some other murky crime fiction sub-genre distinctions, such as hardboiled detective stories vs. noir. Over the next few weeks, we’ll post about some of these other sub-genres. A few of these posts will be encores by various mp authors; some will be new posts.

Readers, what crime fiction sub-genres do you like best, and which ones do you feel have murky boundaries?

And Here’s Our “Celebrating Our Books of 2022” Contest

Grand Prize Winner gets:

  • 8 Signed Paperbacks!*
  • A lovely Autumn tote bag!

Plus 2 other winners get a signed paperback (winner’s choice**)

Runs from 11/5/22 to 11/26/22

Five entries total ~ 3 ways to enter

*You can check out the books at our bookstore here. **Some restrictions apply.

Click HERE for more details and to Enter. Good Luck!

Posted by Kassandra Lamb. Kassandra is a retired psychotherapist turned mystery writer. She is the author of the Kate Huntington psychological mysteries, set in her native Maryland, and the Marcia Banks and Buddy cozy mysteries, set in Central Florida. Plus she has started a new police procedural series, also set in Florida—The C.o.P. on the Scene mysteries. And she writes romantic suspense under the pen name of Jessica Dale.

Misterio press produces an array of quality crime fiction. We post here twice a month, usually on Tuesdays, to alert you to new releases, to entertain, and to inform.

Please follow us (via email, upper right sidebar) so you don’t miss out on new books and other interesting or fun stuff! (We will not lend, sell nor otherwise bend, spindle or mutilate your e-mail address. 😉 )

To see our Privacy Policy click HERE. 

You Might Also Like


  • Reply
    Barb Taub
    November 8, 2022 at 3:33 am

    What I like best are series—cozy or traditional—where we get a chance to see the detective and his/her posse grow and develop over time. I prefer to avoid graphic and/or gratuitous violence and sex. This might explain why I love your series!

    • Reply
      Kassandra Lamb
      November 8, 2022 at 4:19 pm

      Aww, thanks!! They’re my favorites too, although I’m having fun writing the new police procedural series. I like new challenges!

      And Judith and her posse are definitely going to grow and develop. I’ve created a new sub-sub-genre, I think…character-driven police procedurals. 🙂

  • Reply
    judith barrow
    November 8, 2022 at 4:09 am

    I like a story where crime and the result of crime is shown within families. Which is why I prefer what is know as domestic noir. I avoid over explicit violence and gore; if a writer can only appeal to a reader by such graphic detail, I feel it lacks all the other layers that make up a great plot. I enjoy your work, by the way.

  • Reply
    Kassandra Lamb
    November 8, 2022 at 4:22 pm

    Thanks, Judith!!

    Hmm, domestic noir… I’m a little afraid to tackle describing all the variations of noir. But I will try in a future post.

    And I agree, graphic gore is not the best way to attract readers, or at least, not the kind of readers I want to attract.

  • Leave a Reply

    This site uses Akismet to reduce spam. Learn how your comment data is processed.