Listeners of the Writing Excuses podcast are probably familiar with Orsen Scott Card’s MICE quotient, which categorizes elements of your story as Milieu, Inquiry, Character, or Event.
But I want to talk about a different MICE—one that’s uniquely relevant to the murder mystery writer, and borrowed from counter-espionage strategies developed during World War II.
MICE describes the four primary motives driving someone to commit espionage: Money, Ideology, Coercion, and Ego. These are still the central focus of security clearance investigations in the U.S. They also happen to be, on a higher level, the same primary motives driving someone to commit murder.
Money
Murder for money means more than just paid assassins. Your murderer could want their inheritance a little earlier than expected. They could want to protect their assets in a divorce. They could want the contents of their victim’s wall-safe or a particularly valuable piece of jewelry. While this is probably one of the most common motives for murder in the real world, it can also be too simplistic on its own, and unsatisfying for your reader without layering more complex motives, such as Ego or Ideology.
Ideology
Ideology is a complex motive for murder that lets you, as author, explore broader societal conflicts and dig deeply into darker premises. Is there a deep schism in your murderer’s religious community and they must kill their opponent “for the greater good?” Did the victim betray their community and way of life? Are they an interloper who threaten the community’s traditions? Is your murder a hate crime?* You can see how this motive is strong enough to hold it’s own, but it also layers well with other motives, particularly Ego.
Coercion
This is the motive that I find writers using when they want their murderer to be sympathetic. Usually, the murderer is being blackmailed, exploited, or abused, and the only way out is by killing the person who controls their fate. Another common twist on this motive is for the murderer to be a pawn for someone else, coerced into murdering someone to protect their own life or (more sympathetically) their family or loved ones. This allows the murderer to remain a decent person in the eyes of the reader/viewer, because the decision to kill arose from sheer desperation or self-preservation.
Ego
While this motive stands alone, it also works as a second layer for any of the other motives. Ego involves the preservation of a person’s self-image, rather than physical self-preservation. Perceived disrespect drives these murderers, because their own self-image is fragile enough that if they allow the disrespect, it makes them question their worth, attractiveness, competence, or status. It allows you as a writer to play with social status, societal hierarchies, and even toxic gender, class, and relationship roles.
Ego is what drives your murderer to kill their cheating spouse (or their lover), or the person who rejected their intimacy. Some motive models list these crimes as “love” or “passion,” but it’s important to understand that what’s really driving the murder is the person’s bruised ego and self-image. They are angry over the hurt and feel diminished. They need to assert dominance and control. That has nothing to do with love.
How to use MICE
Murders are personal. They’re visceral, and the stakes should be high. But once you determine your murder motive, understanding the underlying MICE drivers will help you make that motive realistic, consistent, and clear. Murders are often executed with baroque complexity, but the psychological drive behind the decision to kill is what makes your murderer interesting.
*If you are using an ideology motive that affects a real-world marginalized group, please make sure you consult with an expert from within that group to ensure you are not falling into a lazy writing role of exploitation or stereotype.