Why Did They Do It?
and why we feel a need to know
One reason often cited for the lasting popularity (almost two centuries) of detective stories is that they satisfy people’s sense of order. In modern fiction this doesn’t always mean justice or retribution; people who do wrong sometimes get a pass or don’t pay the full load for their transgressions. Our grandparents might have scoffed at the idea of a free ride, and upholders of the Hays Code would have wagged their collective disapproving finger, but current readers and viewers are more forgiving. We have generations of anti-heroes in our background.
Still, the notion of order remains, in a slightly amended version. Detective stories convey the message that the world can be understood, that mysteries, if human-made, can be decrypted and resolved. That we have a degree of control. It is reassuring because real life doesn’t provide much of that.
Take any high-profile case splashed over your screens.
The first question, ‘who did it’, will be answered, most of the times. How they did it, gets handled too. But the why, the what made them do it … is where it gets blurry. The great basic drivers of crime fiction, greed and jealousy, rarely make headlines, unless the money is really big or the victim/suspect famous. People with trigger tempers who lose it in a fit of rage don’t get a lot of media airplay either. It’s the other stuff that keeps audiences enraptured. The hard to explain cases. Because we want to understand, it’s in our nature.
We want to know what makes a person tick and what caused them to go off the rails. Why they took the fateful step, why they behaved in a way that’s hard to comprehend. Probably we wonder about ourselves. We want cause and motive. Satisfying answers are hard to find despite all the pundits chiming in and the 24-hour news cycle. They’re mentally ill. Voices told them to do it … Over time, comic books have been blamed, violent movies, video games, online porn, TikTok, and now AI. The quest for cause and motive continues. And conspiracy theories, inevitably. When you can’t get the answers you like, you manufacture your own. What every tinfoil hat wearer wants is to understand. And some version of the truth, forever out of reach.
Not unlike fictional detectives and their readers. How would you rate your favorite sleuth if he/she left you hanging at the end of the book, with a shrug and quipped: ‘Oh, there’s nothing to it, they’re just nuts.’ Wouldn’t you think that character is a dweeb? Pull their license and send them back to PI school, or their rose garden if they’re an amateur in a cozy.
In a recent story published in the Celluloid Crimes anthology, Garbo’s Ghost, I let my character, homicide detective Tom Keegan, react like a real-life harried and tired cop. He’s seen too many gruesome crime scenes. He just wants to go home:
Freddy couldn’t understand why Tom was leaving so soon.
“You don’t want to know who they are and why they did it? Why they took the shoes and where they hid them? They’ll talk, Tom. It’s the only way they can hope to avoid the gas.”
“Killers never have anything interesting to say, Freddy. I plan to get so drunk that by tomorrow I won’t be able to remember their names.”
I don’t feel bad doing this in a short story. Endings that don’t check all the boxes are allowed. In a book, after 300 pages, and readers invested in the characters and the plot, some kind of explanation is required, otherwise it smells like cheating.
Book 2 of the Declan Shaw PI series, Catch Me on a Blue Day, is the hunt for a killer, across time and borders. At the root, there’s a thirty-year-old cold case and a connection to the Salvadoran civil war. Both events have dramatic repercussions in the present. The story starts with the suspicious suicide of a veteran frontline reporter. He was writing a book on Central America that promised to be explosive. Declan Shaw who was hired to help with research for the book uses fragments of the manuscript, notes, and conversations to build the case and zero in on the murderer.
Protagonist, antagonist, supporting roles … I believe that to make characters real, the writer needs to feel some empathy for them, however reluctant, and an understanding of their predicament. Their underlying motive. In Catch Me on a Blue Day, the villain is a homicidal maniac with few redeeming qualities. But he is not irrational and should not be shrugged off as a lunatic on a killing spree. The horrible cold case murder was an act of rage and revenge by a proud man being repeatedly rejected and humiliated. It is the reason for the crime, as the killer sees it and justifies the act to himself. The violence that follows is his reaction to the fear of being found and caught. Monsters never picture themselves as such.
There is logic in the madness, and because the murderer is coherent, in his twisted version of the world, the detective can follow in his footsteps and unravel the mystery.
Find the motive, crack the case. It’s what we all wish for.
(A version of this post was published on the the blog Kevin’s Corner)
Mentioned in this text:
Garbo’s Ghost was published in the anthology Celluloid Crimes. It’s the winter of 1951. Tom Keegan is sent to L.A. to help with Chief Parker’s efforts to clean up the LAPD. The brutal murder case he was working in San Francisco finds ramifications down there. There are shades of James Ellroy in this one …
An essay on this story was published this week in Art Taylor’s The First Two Pages, and yes, you can read the beginning of the story. It’s all here.
Catch Me on a Blue Day has been out for a few weeks now. If you’ve read it, leave a review on Amazon or Goodreads, it helps a lot! If you haven’t picked a copy yet, you can get it here.


Interesting. I'm currenly editing (and editing and editing) a novel where the motive is left somewhat cloudy. She's a supernatural character who thinks humans are stupid, and wouldn't lower herself to explain fully ... I hope that works.
"It’s the only way they can hope to avoid the gas.” The gas chamber? Those iron doors like a submarine? Now there was a scary execution.