From Whodunits to Locked Rooms: Types of Mystery Fiction

May is National Mystery Month! If you're already a fan of mysteries or just jumping into the genre, you have plenty of subgenres to choose from. Below are some popular subgenres of mystery fiction, each with a popular example. But choose whatever your little investigative heart desires. Check out our mystery page for more.

Detective & Whodunit Mysteries

Detective fiction (a common type of mystery)needs to be solved by police or private detective(s). Clues, red herrings, and some plot twists are expected along the way. A "whodunit" is a type of detective story where the reader is given clues throughout the book as to who the culprit is, giving the reader the opportunity to solve the crime before the solution is officially revealed.

In the Woods by Tana French
Dublin, 1984. At dusk, three children vanish in the woods. Only one makes it out--Rob Ryan, who grips a tree trunk in terror and is unable to recall any details of the previous hours he's endured. Twenty years later, Rob, now a detective on the Dublin Murder Squad, tries to keeps his past a secret. But when a young girl is killed in the same woods, Rob must investigate the present--and his past.

Hard-boiled Detective Fiction

Hard-boiled fiction started in response to a period of organized crime that flourished during Prohibition (1920–1933) and its aftermath and includes dealing with a legal system that has become as corrupt as the criminals themselves. The detectives of hard-boiled fiction are often antiheroes. A related subgenre is noir.

The Big Sleep by Raymond Chandler
This is the first book to feature private detective Philip Marlowe, who is hired to untangle a messy web of deception involving a wealthy family. Marlowe encounters a plethora of crime, corruption, and seduction in the underbelly of 1930s Los Angeles. This book has been adapted into film many times, including the popular 1946 version starring Humphrey Bogart and Lauren Bacall.

Police Procedurals

A police procedural is similar to detective and hard-boiled fiction. Most often they depict routine activities of a group of police officers who are working on a case together. Some of these stories are whodunits, but in others, the criminal can be well known, and it's a matter of tracking them down. Like hard-boiled fiction, police procedurals can be violent in nature, with graphic descriptions of crime. A similar subgenre is the legal mystery where lawyers and others in the legal professions work to solve the crimes.

The Alienist by Caleb Carr
New York City, 1896. This historical mystery follows "alienist" Dr. Laszlo Kreizler and John Moore, a crime reporter for the New York Times who lead an investigative team attempting to solve a series of gruesome murders through new methods, including fingerprinting and psychology. Featuring future President Theodore Roosevelt--then New York City police commissioner.

Locked-Room Mysteries

A sub-subgenre of detective fiction, a locked-room mystery almost always features murder committed in such a way that it seems impossible for a perpetrator to have done so without being seen. Poe's The Murders in the Rue Morgue, opens a new window (1841) is considered the first locked-room mystery. 

The Hunting Party by Lucy Foley
Continuing a tradition they started 10 years ago as students, a group of friends from Oxford meet to welcome the New Year together. For this vacation, they've chosen an isolated grand estate in the Scottish Highlands. But after a decade of these get-togethers, old resentments have risen to the surface, and secrets are beginning to be unearthed. The ties holding them together begin to break just as a massive blizzard hits. After the storm is over, one of them is dead... and another one of them was the murderer.

Cozy & Amateur Sleuth

Cozy mysteries generally stay away from overt violence and suspense and frequently feature female amateur detectives in small communities with a cast of repeating characters. If there are any murders, they are often committed by less obviously violent means, such as poison. Cozy mystery series may go on for many volumes and can feature funny titles and underlying humor., opens a new window details these mysteries, as well.

Agatha Raisin and the Quiche of Death by M.C. Beaton
In this first book of the popular Agatha Raisin series, early retiree Agatha Raisin settles down into the quiet village of Carsely. When she enters a local baking contest for the best quiche in town, the judge dies after eating--and snubbing--her quiche. Agatha discovers that someone slipped poison into it before the contest, and she's determined to find out who it was and why they wanted the culinary judge dead.


Howcatchem, or an inverted detective story, is a subgenre in which the commission of the crime is shown or described at the beginning of the story and usually includes the identity of the perpetrator in the first chapter. The story details attempts to solve the mystery. This interesting format was developed in the story The Case of Oskar Brodski, published in Pearson's Magazine in 1912. It is considered the opposite of the more typical "whodunit."

Mr. Mercedes by Stephen King
Brady Hartsfield plows a stolen Mercedes through a crowd of men and women waiting in line for a job fair, leaving eight dead and dozens wounded. For years, the case goes unsolved, and ex-cop Bill Hodges is out of hope--until he gets a letter. Brady is out to do it again--but this time, his goal is to kill and attack thousands--unless Hodges can stop him.

True Crime

Although it is considered nonfiction, true crime is where the above genres draw their inspirations. In a true crime book, the author examines a crime and details the actions and people affected by it. Nowadays, the genre is widely associated with podcasts. The crime descriptions are very brutal and most, but not all, go into gritty details.

Down the Hill: My Descent into the Double Murder in Delphi by Susan Hendricks
Former CNN/HLN anchor and broadcast journalist Susan Hendricks takes a deep dive into investigating the 2017 double homicide of two teens in Delphi, Indiana.

Note: In October 2022, there was an arrest made when evidence was tied to a man named Richard Allen, who eventually confessed to killing Abby Williams and Liberty German.

If you're looking for more mysteries to browse, check out our database Novelist (with your library card) or ask a librarian for a suggestion.