Writing a Convincing Culprit

by Harrison Demchick, @HDemchick

Have you ever read a mystery where the culprit’s motivations made no sense at all?

Or how about one where the culprit is caught because he did something he would never plausibly do?

I’ve seen quite a lot of this in the mysteries I’ve edited. Mystery is a genre of logic, and a good mystery is a puzzle waiting to be solved, but where that puzzle so often falls apart, particularly in early drafts (and even for very talented writers), is with the culprit. And the reason is that, very often, the actions of the culprit serve the story rather than the character.

There’s a reason for that. In most fiction, we develop our story around the protagonist. It’s the protagonist with whom we spend most of our time, and if there’s a character arc, it’s usually hers. The experience of the novel is defined by her actions and experience.

But mystery is a little different, and the reason it’s different is that it’s the antagonist’s actions that really drive the story. The culprit commits the crime, and the detective reacts. That’s not to say that the detective is inactive—she’s certainly trying to solve the mystery, and ultimately both characters are reacting to one another (even before we know who the culprit is)—but fundamentally, the detective’s story is unraveling the culprit’s story. And that means that you, as author, need to know the culprit’s story as well and as clearly as the detective’s.

Moreover, that story, and the character who lives it, need to make sense.

Question #1: Who is this guy, and what’s with the bunny ears?

Think it’s a cool idea for your killer to wear bunny ears and sunglasses? Fair enough—but you’ve got to know why. Childhood love of bunnies? Ardent Bugs Bunny fan? Or is it just that he loves the look of confusion in the eyes of the people he kills? Any of it can be valid, but you need to be careful not to bind yourself to a cool image without understanding the character underneath it.

I edited a novel once that featured a killer who dressed as a priest. It was a compelling visual, but it was never really explained, and in the end it didn’t seem to fit the character in any way, so it didn’t work.

The culprit is a character like any other. He has wants and needs that define his goals, and the actions he takes, consciously or unconsciously, are in service of those goals.

Question #2: So what does he do about it?

Simple answer: Whatever he wants to do.

The central problem with a lot of culprits in a lot of mysteries is that their actions are designed to push the story in the direction in which the author wants it to go. A killer spends most of the story eluding the police with astounding intelligence and care, but then, because it’s time for the story to end, strolls by the police station wearing a T-shirt that says “I killed all those people.”

Okay, that’s an exaggeration. But consider that mystery I edited. Priest costume aside, the killer always struck at night and always used poison—until the last third of the story, where the killer suddenly struck during the day with a gun. In the climax, the killer used poison again, but this time in broad daylight at a crowded party. Why? Because we were getting near the end and the author wanted the detective to catch the killer.

A culprit is not going to kill just to give the detective another murder to consider (unless, of course, he’s intentionally playing a game with the detective). He’s not going to change his modus operandi in order to leave that crucial bit of evidence that had otherwise been eluding the detective—the break in the case the story demands. He’s going to serve his own needs. He’s going to kill, or steal, or whatever he does because he wants to—because it helps him cleanse society of those he deems sinners, or take over his family’s business, or repeat the psychologically ingrained murder of his wife.

This doesn’t mean that your culprit is an unchanging monolith. The culprit is a character, and as such, he reacts to things. He reacts to the detective getting close. He reacts to extraneous circumstances. He’s human. But it’s got to make sense within the context of his own story.

Question #3: So does that mean all mysteries should be written from both characters’ points of view?

Not at all. I’m not saying you need to write your mystery from the culprit’s perspective. But you need to know it. Readers may never see that parallel narrative, but they do need to see a culprit who is living it—one who is the protagonist of his own story, as most characters are. The culprit’s story may not be your story, but it is the logical foundation of your story, and you can’t craft a compelling mystery without knowing, at all times, who your culprit is and why they do what they do.

In other words, the culprit doesn’t serve your story. He is your story. Understand him and good things will follow.

Harrison Demchick came up in the world of small press publishing, working along the way on more than three dozen published novels and memoirs, several of which have been optioned for film. An expert in manuscripts as diverse as young adult, science-fiction, fantasy, mystery, literary fiction, women’s fiction, memoir, and everything in-between, Harrison is known for quite possibly the most detailed and informative editorial letters in the industry—if not the entire universe.

Harrison is also an award-winning, twice-optioned screenwriter, and the author of literary horror novel The Listeners (Bancroft Press, 2012). He’s currently accepting new clients in fiction and memoir at Ambitious Enterprises (http://ambitiousenterprises.com).