How Many Suspects Do You Need In A Crime Novel?

When we read or write crime novels, we want to find out who the baddie is. This means we need suspects from which to choose. But how many suspects do you need in a crime novel? We’ve also included common murder suspect archetypes for you to use in your book.

How Crime Fiction Works

Crime fiction is usually divided into mysteries, thrillers, and horror stories.

1. Mysteries are stories when the crime has already been committed and a detective-type character (amateur sleuth, private investigator, police detective, etc.) tries to solve it.
2. Thrillers are stories when a crime is about to be committed and your main character must try to stop it from happening.
3. Horror stories are when a crime is being committed and the reader is forced to watch the protagonist go through the terror and try to stop the perpetrator.

Whatever type of crime fiction (and their many sub-genres) you choose, you need suspects for the protagonist to interview, chase down, or stop. And you need enough of them to keep the reader interested.

Must-Read: Mystery, Horror, Thriller – What’s The Difference?

How Many Suspects Do You Need In A Crime Novel?

Now that we’ve established there is a crime, we need to include great suspects to keep the story going for 80 000 words.

‘A suspect is a known person accused or suspected of committing a crime. … The term is also related to the terms defendant, the accused, person of interest, and prime suspect.’ (Wikipedia)

Five plausible suspects seem to be the number that most novelists choose.

1. Cozy mystery author, Elizabeth Spann Craig says: ‘If you have more suspects, you can more easily maintain the element of surprise at the end, but you have to be careful not to confuse the reader. I usually prefer 5 suspects, killing one of them during the course of the book.’
2. Novelist and Executive Director of Crime Writers of Canada, Melodie Campbell says: ‘Every mystery novel needs at least three good suspects that you can’t dismiss out of hand… Five is even better, particularly for a full length novel.’
3. Atmosphere Press says: ‘Most successful mysteries feature between four and seven suspects. Too few, and the solution becomes obvious; too many, and readers get lost.’

Fewer than five suspects do not challenge the reader enough. We want them to wonder who committed the crime and to go along with the detective or sleuth for the full length of the novel. More than five can be too many in a book. This can bore your reader and they will lose interest.

People can usually remember four suspects well. So use five, but concentrate more on the four most likely culprits. We are able to easily remember the names, addresses, connections to the victim, and motives of four people.

(In films, it is common to have more suspects, sometimes up to 10. Glass Onion, A Knives Out Mystery has eight suspects.)

9 Common Archetypes For Murder Suspects Include:

1. The Disgruntled Relative: This person of interest is a classic character trope in crime fiction who has a hidden reason to hate the victim. They may have been cut out of a will or treated badly. They appear to be grieving, but they really have a powerful motive for murder.
2. The Best Friend: This suspect is rarely thought of as the killer in the beginning, but secrets begin to emerge, revealing them to be a plausible perpetrator of the crime. A betrayal of some sort is usually involved.
3. The Heir: This character is another common trope motivated by inheritance, power, or covering up financial crimes. The heir to the victim’s money may need it to get out of trouble – or simply because they dislike the power the person holds over them.
4. The Business Partner/Colleague/Boss: This suspect might have been involved in an illegal deal with the victim. The victim’s death could also stand to benefit them financially. They often provide a strong alibi that the detective struggles to disprove.
5. The Secret Lover/Rival: The person of interest could have been involved in an affair with the victim, or a rival in a love triangle. Keeping this romantic secret from loved ones is the primary reason they lie to the authorities.
6. The Authority Figure: This could be the police officer, butler, or doctor who seems above suspicion, but knows damning secrets relating to the victim.
7. The Disgruntled Employee/Servant: This suspect is often overlooked, but they’re closely acquainted with the victim’s routine and the murder setting. Their motive usually stems from being mistreated or the victim creates a sudden, negative change in their circumstances.
8. The Outsider With A Past: This character might be new to the victim’s immediate circle, but has a mysterious past connection that provides a motive. They often serve as a red herring, with their suspicious actions designed to distract the reader from the true culprit.
9. The Serial Killer: This character is the most difficult one to write as the victim seldom knows them.

The General Red Herring Suspect: This person of interest could be any of the above and is designed to look guilty with a strong motive, a lack of alibi, and a compromising situation. This diverts attention from the real killer. They are often mistakenly arrested during the course of the story.

N.B. Each suspect must have:

1. A motive for committing the crime. Their motives must be believable and have enough weight for them to be considered in the first place. Remember that murder is the usual crime committed in mysteries, thrillers, and horror stories, so the risk is very high for the character. What motivates them to make their choices? To act and to react? Their motivation should matter, be complex, be rational or irrational, but be believable. The usual reasons for murder are love, money, secrets, resentment, and revenge. You can use our post: 7 Deadly Sins To Strengthen Your Antagonist’s Motives if you like.
2. A link to the victim. Unless you’re writing a random serial killer mystery, the victim and the suspect should know each other. It must be plausible that their paths will cross and that the crime could take place. This usually gives them the opportunity to commit the crime.
3. Access to the murder weapon. This usually gives them the means to commit the crime.
4. The ability to commit the crime. This could be as simple as a matter of strength if the murder was committed against someone much stronger than they are.
5. A reason to be in the book – use sub-plots here. The suspects could be: a love interest; a person who reflects a character’s growth; a person they employ; a person with whom they share a habit or addiction; someone who knows their secret fear; someone who has grown close to them through a shared dream; or someone they have betrayed. The usual suspects include family members, friends, and work colleagues.
6. A great introduction (by the author). We have to remember them so the author must make them memorable. You could have your detective-type character interact with them before the murder, you could have a non-suspect giving a list of likely perpetrators (and maybe their reasons for committing the crime), or you could have one suspect suggesting more suspects. On meeting the suspects, make sure that their names are distinctly different from each other, mix their sexes, give each one a quirk or a trait that is memorable. They may have a way of dressing or behaving that is difficult to ignore. They may also have a physical feature that is difficult to forget. They may live somewhere that is interesting.
7. An alibi (or not). Alibis are good ways of ruling out suspects. You can use witnesses, video footage from security cameras, their presence on social media, and physical evidence such as fingerprints or DNA to clear them. Not having an alibi can make them easy targets for red herrings.

Tip: Use red herrings that seem to implicate or clear a suspect. A good red herring could either implicate the wrong person or give a reliable alibi for the real murderer. This makes your protagonist think they’ve caught the killer or discount them as a suspect.

The Last Word

These characters must be interesting. We should remember their interviews, their lies, their truths, and their false leads. At the end of the novel, there will be one suspect left who is guilty. The trip towards this destination should be intriguing.

by Amanda Patterson
© Amanda Patterson

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