One of the things I love about murder mysteries – traditional mysteries such as those I write, cozy mysteries, police procedurals, noir, all of them – is that the investigation is simultaneously crucial to the story and tangential to it.
The mystery, the puzzle the detective – and the reader along with her – has to solve is “whodunit”?
But before that, long before the butler is strangled or the chef chopped up or the heiress shot, before any of those things, there’s another story. The story behind the crime. The story of the criminal.
The detective who solves the puzzle is the protagonist. He examines the dead body, sees the scene of the crime. She must dig up clues, talk to witnesses, learn about the character and background of the suspects. That all happens on the page.
The other story, embedded deep within the surface story, is the story of the criminal. In my books, this person’s story starts long before the detective shows up. A wrong was endured, for example. Or an innocent mistake made. A mistake that snowballs. That propels someone inexorably toward murder.
As an author, I can’t simply go back and write that story. It would ruin the puzzle! It’s a hidden story. Somehow, I have to find a way to paint a picture of events happening now in a way that exposes events of long before.
Telling the killer’s story means revealing feelings, actions and thoughts that led the killer to commit the crime. Exploring the passions that drove him months, perhaps years, earlier. But telling them in such a way that the reader experiences them as if they were new, fresh wounds.
That’s the story within the story of any murder mystery. The story of the killer. A story of pain, despair and ultimately a story of evil. A story that unfolds, bit by bit, piece by piece, as the detective unravels the killer’s lies, exposes the killer until his story rises to the surface.
The detective’s story and the killer’s story intertwine. By the end of the book, the two stories collide. The puzzle pieces all fit together.