The modern mystery genre embraces several distinct subgenres — the police procedural, the cozy, the thriller, the crime caper, the classic whodunit, and maybe a couple others that I’m forgetting. All of them are somewhat formulaic, so if you’re going to write one, you need to know the conventions of your chosen subgenre.
I’m partial to whodunits. You don’t know who the murderer is. It could be anybody! The sleuth doggedly plods down blind alleys in search of the subtle clue that will unmask the killer.
The whodunit has its share of conventions. Often, the person you, the reader, think must surely be the killer turns up as the second corpse. Dodgy alibis are a staple. But two conventions are even more basic. First, in the grip of strong emotion almost anybody can resort to murder. It doesn’t require a special value system or a clinically defective moral compass. Second, someone who can kill or has already killed looks exactly like anybody else. There are no visible behavioral cues that will suggest to the sleuth or to the reader that this person is seriously unbalanced.
These ideas are probably not good human psychology, not in the real world. But if you try to discard them, it’s going to be difficult to write a whodunit.
A whodunit can work well if there are only two viable suspects, but it’s usually better to have three or four. (Having five suspects gets unwieldy.) The trick is to make the suspects believable as potential murderers. But really, how many people can be so horribly vexed by the person who is about to die that they might plausibly pick up a dagger or a pistol?
In most respects I’m a fairly normal human being, though I’m probably more rational and less swayed by emotion than some. I find it difficult to put myself in the shoes of a murderer. I’ve written a couple of whodunits, and I think I did the suspects pretty well. If you’d like to check out whether I’m kidding myself, you can jet over to Amazon and pick up While Caesar Sang of Hercules or Woven of Death and Starlight. But those stories both have exotic settings, which probably makes it more plausible that seemingly ordinary people are crazy enough to kill.
At the moment I’m contemplating a story set in upstate New York in the modern era. My story idea has some features that I really like, including the snarky voice of the first-person narrator. But I’m going to have to think about the deep emotions of the killer(s), because I want the story to be believable.
I’m fairly obsessive, in fact, about believability. Not all mystery writers are. This week I’ve been binge-reading (re-reading) Rex Stout’s Nero Wolfe mysteries. The main attraction of these classic whodunits is the contentious relationship between Wolfe and Archie Goodwin. Sometimes the plot makes sense, but no guarantees. In And Be a Villain, we’re expected to swallow the idea that the cops never asked anybody why one of the soft-drink bottles had coffee in it rather than the expected beverage. And the third murder, while dramatic, was flatly unbelievable. The killer could not possibly have imagined that that would be a viable way to do away with the victim.
There may be a lesson in this. Stout was very successful, and the Wolfe books are classics. Mysteries are an entertainment product. If you can entertain (and as a narrator, Archie Goodwin is vastly entertaining), you can get away with murder.
Jim Aikin's Oblong Blob 