Hardboiled mystery novels are those that tell gritty, typically violent, stories from a more tough and cynical tone. They aim to be realistic in the moral ambiguity of the characters and their journeys for justice. This genre often includes: tough, cynical protagonists, dark/gritty setting, violence and corruption, moral ambiguity, and hard-hitting dialogue.

Examples:

The Big Sleep by Raymond Chandler

The Maltese Falcon by Dashiell Hammett

The Lincoln Lawyer by Michael Connelly

Cozy mystery fiction takes a lighter, charming approach to crime fiction. The protagonists are often amateur sleuths, as opposed to professional detectives. The stories typically take place in small towns or close-knit communities and are told with more upbeat and less violent tone than other subgenres of mystery fiction. This is a good subgenre to pick up when you're looking for mysteries that are more upbeat, character-driven and puzzle-solving, with little to no graphic violence.

Examples:

The Murder at the Vicarage (Miss Marple Series #1) by Agatha Christie

Dead Until Dark by Charlaine Harris

The Maid by Nita Prose

These novels have a more central focus on the legal system as the protagonist (often, a lawyer) attempts to find justice. Much of the drama and suspense will take place in the courtroom and follow the legal procedures and ethical dilemmas that the characters face.

Examples:

A Time to Kill by John Grisham

The Bonfire of the Vanities by Tom Wolfe

While Justice Sleeps by Stacey Abrams

Psychological thrillers focus on the complex relationship between characters and their psyche. They are often told from the perspective of an unreliable narrator, whose personal struggles guide the plot to create intense moments of tension and suspension for the reader. Authors of these stories make a point to keep the audience on their toes with twists and turns and blurred perceptions of various characters and events.

Examples:

The Girl on the Train by Paula Hawkins

Gone Girl by Freida McFadden

The Woman in the Window by A.J. Finn