Whodunit? Mysteries, Thrillers, and Crime

The first thing to note about these genres is that they’re always getting mixed up. There’s been much debate over the years about what exactly defines each genre. Here’s a few clues to cracking the case! 


A crime is committed—almost always a murder—and the action of the story is the solution of that crime: determining who did it and why, and obtaining some form of justice. These are puzzles to be solved through investigation of some kind. This is usually the least violent of the three genres.


A thriller novel devotes most of its focus to suspense, dread, and the fear of a future crime—instead of one that’s already happened. In a thriller, the bad guy is often established early on, and the main characters must work to stop them from doing evil. Crimes may still occur, but it’s more about the chase rather than solving the case.


In this genre the focus is on the contest of wills between the lawman hero and the outlaw villain, and their differing views of morality and the aspects of society they represent. The greatest crime stories deal with a moral accounting on the part of the hero for his entire life, or provide some new perspective on the tension between society and the individual. Like thrillers, this is about the chase. However, it is more of a cat-and-mouse type of narrative, where we know early on who our “hero” and our “villain” are.

These three genres certainly cross over, but each has unique qualities that appeal to different readers. If you’re looking to “participate” in solving a crime or many crimes, mysteries are for you. If you want to see the hero and villain in battle, crime novels are right up your alley. If you want to see the protagonist save the day before (or soon after) complete mayhem and destruction ensue, thrillers are the way to go.

It is important to note that horror is an entirely different genre of its own. While there could be horror elements within mysteries, thrillers, or crime novels, they are not defined as horror. Thrillers come closest to the horror genre because they evoke dread in the reader; however, thrillers provide more action sequences throughout the plot.

Since these genres can cover a multitude of categories, many subgenres have emerged:

Police Procedural:

The hero of the story is a police force/unit. The hero tends to be more world-weary than bitter—but that ice can get slippery. Special focuses are on police tactics, squad-room psychology, station-house politics, and the tensions between the police and politicians, the media and the citizenry.

Sworn to Silence by Linda Castillo

The Unquiet Dead by Ausma Zehanat Khan

Cozy Mystery:

These stories almost always follow an amateur sleuth who does not usually solve mysteries, i.e. a baker, a librarian, a retired teacher, etc. Usually set in an idyllic small town or a subset of a larger community, most of the main characters know each other, which makes the crime (usually a murder) all the more shocking. However, these mysteries do not have gory violence, profanity, or sex. Justice triumphs in the end, and the world returns to its original tranquility.

A Deadly Inside Scoop by Abby Collette

Death by Dumpling by Vivien Chien

Locked Room Mysteries:

“In a "locked room" mystery, a murder (or other crime) happens in a room that seems to be completely, well, locked to the outside world; typically from the inside. So in order to solve the crime, the detective has to figure out not only who committed it but also why the scene of the crime is a locked room in the first place, and how the perpetrator managed to get in and out of the room and leave it behind apparently locked from the inside. -- Sometimes, the locked room is also used as a decoy or in order to provide the murderer with an apparently unbreakable alibi for a crime committed somewhere else” (Goodreads).

They All Fall Down by Rachel Howzell Hall

An Unwanted Guest by Shari Lapena

Hard-Boiled Detective:

Hardboiled crime novels are realistic and usually feature a tough private eye, detective, or police officer.  The moral view is often that of hard-won experience in the service of innocence or decency.

The Maltese Falcon by Dashiell Hammett


The “hero” finds himself/herself/themselves in some sort of desperate situation, or is tempted into one by an opportunity he sees as his last, best chance at the brass ring. The lure of sex or money routinely leads to violence and often betrayal. If the hero is a cop, the reader is never quite sure whether he’s/she’s going to solve a crime or commit one. Or both.

Devil in a Blue Dress by Walter Mosley

The Devil All the Time by Donald Ray Pollock

True Crime:

These crimes stories, which cross-pollinate with the historical fiction genre, tell tales of crimes that actually happened at some point in history. The real-life non-fiction origins of these crime thrillers heighten the stakes and grip readers.

In Cold Blood by Truman Capote

Savage Appetites by Rachel Monroe

Psychological Suspense Thrillers:

Here, the threat is still diabolical but more contained, even intimate—usually targeting the protagonist and/or his family—and the hero is often a relatively “ordinary” man, woman or child. This is an extremely popular subgenre in books, movie, and T.V.

I Am Watching You by Teresa Driscoll

The Lost Ones by Sheena Kamal

Legal Thrillers:

“The legal thriller is a sub-genre of thriller and crime fiction in which the major characters are lawyers and their employees. The system of justice itself is always a major part of these works, at times almost functioning as one of the characters” (Goodreads).

Miracle Creek by Angie Kim

A Gambler's Jury by Victor Methos

Supernatural Thrillers:

This subgenre is something of a hybrid, in that the nemesis presents an overwhelming threat—he might be Satan himself—and yet that threat is often focused on a single soul or a mere few, rather than the whole of mankind, at least within the story.

Within These Walls by Ania Ahlborn

The 7 1/2 Deaths of Evelyn Hardcastle by Stuart Turton

YA Mysteries/Thrillers:

There are many great YA mysteries and thrillers out there! Sometimes, the only difference between these and their adult counterparts is the age of the characters. From action-packed thrillers to locked room mysteries, YA is definitely a must for readers of the genre(s).

One of Us Is Lying by Karen M. McManus

Even If We Break by Marieke Nijkamp

Here are some Fun Facts:

  • Agatha Christie is the best-selling author of fiction, selling an estimated 2 billion copies of her 78 crime novels.
  • Christie is also the most-translated author, whose works have been translated in at least 103 different languages.
  • While elements of mysteries, crime, and thriller genres have been around since the 5th Century B.C., it is Edgar Allan Poe’s short story “The Murder in the Rue Morgue” that is considered to be the first modern detective story, which was published in 1840.
  • The mystery genre became popular in the 1880s through Sir Arthur Conan Doyle’s stories starring the now-famous Sherlock Homes.
  • Alfred Hitchcock is the only non-mystery author to be given the title of The Edgars Awards’ Grand Master in 1978.

Links that can help you find more mysteries and thrillers to read:

More Mystery & Thrillers at the Library!

Get Started With Cozy Mysteries List created by PimaLib_RavenousReaders

View Full List Get Started With True Crime

List created by PimaLib_RavenousReaders

View Full List

Get Started With Legal Thrillers

List created by PimaLib_RavenousReaders

View Full List

— Kelsey B, Ravenous Reader