14 Popular Crime Fiction Sub-Genres

Explore 14 crime fiction sub-genres, from cozy mysteries and classic detectives to psychological thrillers and heists.

Crime fiction is one of the most popular literary genres. From locked-room mysteries to psychological thrillers, it offers writers many ways to explore crime, justice, and human nature.

Crime fiction includes stories about crimes that are being investigated. Some focus on discovering who committed a crime, while others explore the motives behind it, the consequences for its victims, or the efforts to prevent further crimes.

In whodunit crimes, a crime has been committed and a murderer, a spy, or a thief must be caught by the protagonist. In a thriller, a crime is about to be committed and the protagonist must stop it from happening. The heroes of these books are professionals or ordinary people called on to solve a problem. Sometimes, they must prove their innocence, often to the police and other characters in the novel.

Crime fiction includes mystery, horror, and thriller fiction. These categories are not mutually exclusive, and a novel can belong to more than one sub-genre.

Here are 14 crime fiction sub-genres to explore when planning your next story.

14 Popular Crime Fiction Sub-Genres

1. Cozy Mystery

In a cozy mystery, the detective is usually an amateur sleuth. The violence is never described in detail, there are a limited number of suspects, and the setting is often a small town. The detective uses their powers of observation and deduction, their proximity to the community, as well as an excellent general knowledge to solve the crime.

Examples: Agatha Christie’s Miss Marples series, G.K. Chesterton’s Father Brown series, Kerry Greenwood‘s Phryne Fisher’s Mystery Series

2. Locked-Room Mystery

A locked-room mystery features a crime that appears impossible. The victim may be found in a locked room, or the crime may have taken place under circumstances seem impossible. In this sub-genre, the how matters even more than the killer’s identity.

The writer must must create a puzzle, plant clues, and show how the crime happened.

Examples: The Twist of a Knife by Anthony Horowitz, Death and the Conjuror by Tom Mead

3. Private Investigator Fiction

Private investigator fiction follows a detective who works independently, often for clients who need help finding people, uncovering secrets, or solving crimes. PIs may be former police officers, bounty hunters, experienced investigators, or people with unusual skills.

Some PI stories are light and humorous, while others are dark and violent.

Examples: Robert Galbraith’s Cormoran Strike novels, Kellye Garrett’s Dayna Anderson mysteries, Janet Evanovich’s Stephanie Plum series, and Jacqueline Winspear’s Maisie Dobbs series

4. Hardboiled And Noir Fiction

Hardboiled crime fiction often features a tough, cynical detective working in a corrupt or dangerous world. The writing is direct, the dialogue is sharp, and the violence can be explicit.

Noir fiction is darker still. Its characters are often morally compromised, and their choices may lead to betrayal, failure, or destruction.

Examples: The Maltese Falcon by Dashiell Hammett and Raymond Chandler‘s Philip Marlowe novels, including The Big Sleep and Farewell, My Lovely

5. Police Procedural

A police procedural focuses on the methods and routines of law enforcement. Readers follow detectives as they interview witnesses, examine evidence, investigate suspects, and work through a case. This detective is often under a lot of pressure. For example, they could be dealing with many cases, they generally have personal problems with relationships, and their superiors want the case solved yesterday.

Accuracy is important. Writers should research police procedures, forensic methods, and the legal system relevant to their setting.

Examples: Ian Rankin’s John Rebus, Michael Connelly’s Harry Bosch, and James Patterson’s Alex Cross

6. Forensic Crime Fiction

Forensic crime fiction uses scientific evidence to help solve crimes. The lead character is usually a woman who is a scientist or pathologist. Research is needed. Accuracy is essential. Most of the action takes place in crime scenes, morgues, and in the lead character’s home.

Writers need to research forensic techniques.

Examples: Patricia Cornwell’s Kay Scarpetta, and Kathy Reichs’s Temperance Brennan

7. Legal Thriller

Legal thrillers focus on the justice system and the people who work win it. The protagonist is often a lawyer who must investigate a case, defend a client, or expose wrongdoing.

Courtroom drama, ethical dilemmas, and conflicts between law and justice are often explored.

Examples: The Firm by John Grisham and Presumed Innocent by Scott Turow

8. Psychological Thriller And Domestic Noir

Psychological thrillers focus on the characters’ minds, motives, and perceptions. The protagonist may be unreliable, and the reader may be unsure whom to trust.

Domestic noir often explores crime and danger within families, marriages, or intimate relationships. Secrets, manipulation, betrayal and power struggles drive the plot.

Examples: Gone Girl by Gillian Flynn and The Girl on the Train by Paula Hawkins

9. Historical Crime Fiction

Historical crime fiction combines an investigation with a past setting. The crime may be solved by a professional detective, an amateur sleuth, or someone who becomes involved by chance.

Writers must research the period’s laws, technology, social customs, and investigative methods.

Examples: C. J. Sansom’s Shardlake novels and The Name of the Rose by Umberto Eco

10. Espionage And Military Thrillers

Espionage thrillers involve spies, intelligence agencies, and national security. Military thrillers often focus on soldiers, military operations, or threats involving armed forces. Protagonists in these sub-genres often include a member of the military, MI5 or MI6, the CIA, the FBI, or a consultant to a military agency.

These stories may involve political conspiracies, terrorism, international conflict, or secret missions. Research into intelligence work, military structures, and technology is essential.

Examples: Tinker Tailor Soldier Spy by John le Carré and The Hunt for Red October by Tom Clancy

11. Heist And Caper Fiction

Heist fiction follows criminals planning and carrying out a robbery or another elaborate crime. The story often centres on assembling a team, overcoming obstacles, and executing a carefully planned operation.

Caper fiction usually takes a lighter, more playful approach, with humour, clever schemes, and unexpected complications.

Examples: The Great Train Robbery by Michael Crichton, The Housekeepers by Alex Hay, Portrait of a Thief by Grace D. Li

12. Amateur Sleuth Mystery

Amateur sleuth mysteries feature ordinary people who investigate crimes without professional training in law enforcement. They may become involved because they know the victim, discover something suspicious, or believe the police have overlooked an important clue.

Unlike cozy mysteries, amateur sleuth stories have darker settings, more serious themes, and graphic violence.

Example: The Caveman’s Valentine by George Dawes Green, A Good Girl’s Guide to Murder by Holly Jackson, and Missing Person by Sarah Lotz

13. Medical Thriller

Medical thrillers feature crimes, conspiracies, or dangerous situations involving medicine, hospitals, or medical research. The protagonists are often doctors or nurses who uncover threats to patients or public health.

Writers need to research medical procedures, terminology, and ethical issues to make the story convincing.

Examples: Coma by Robin Cook and The Surgeon by Tess Gerritsen

14. Classic Detective Fiction

Classic detective fiction centres on an intelligent, often highly observant detective who solves crimes through logic, deduction, and careful examination of clues. The reader is invited to follow the investigation and try to solve the mystery alongside the detective. These stories can include serious crimes, violence, and darker settings.

Examples: The Adventures of Sherlock Holmes by Arthur Conan Doyle, The Moonstone by Wilkie Collins

The Last Word

Crime fiction offers writers plenty of ways to build suspense, create mysteries, and explore human nature. Whether you prefer cozy mysteries, police procedurals, or psychological thrillers, there is a subgenre to suit your story. Happy writing!