Like many voracious readers, I grew up on mysteries. Boxcar Children, Nancy Drew, the Hardy Boys. Of course, that bleeds into murder mysteries as you get older, and for me this led me to television and Agatha Christie.
If there’s one thing I’ve learned about myself as a writer, it’s that murder mysteries – or even just mysteries – are a speciality and a love of mine. For one thing, it gives you a beautiful excuse to kill off characters, and to make everybody seem like suspect sorts of people. It also gives you excuses to dole out information to the reader very slowly.
As my poison-loving (as a writer, not a purveyor) editor and best friend, Natalie Cannon, has told me, the key to writing a convincing murder mystery is to know first of all, whodunit, and how, and why. Just like makers of jigsaw puzzles print the picture out as a whole and then cut it up and jumble the pieces, the writer of a murder mystery has to follow similar steps.
The first step, as I said, is figuring out what happened, what the mystery actually is that everyone’s trying to solve. What it is, what it looks like. Sometimes those are one in the same. Sometimes someone’s killed one way and it’s been made to look like something else. You have to know exactly what’s happened if you’re going to leave the right breadcrumbs. Sometimes, you’ll notice that mysteries will have multiple murders. Both mysteries I’m currently working on are like that, and the one I’m doing for Camp NaNo has two very closely connected murders, whereas my other mystery has about half a dozen murders, much more loosely connected, which makes it a longer and more complicated story. If you’re not sure you can keep all the clues straight, stick to one or two murders, and if you do two, make them very closely connected.
Once you have the murder all sorted out, it’s a matter of figuring out what would leave traces, especially traces that could be misinterpreted. This is the selection of breadcrumbs. It’s important, as well, to decide what sort of murder mystery you’re working with. Will the reader know who the killer is? Will there be a big reveal at the end to (hopefully) stun all but the most astute? In Those We Trust, which is something of a murder mystery, in a way, the killer is a regular voice, but I’m very careful to keep the identity completely secret until the very end. Even the characters never discover who it is, so the breadcrumbs left by the killer are actually deliberate, pointing fingers at everyone else. The reader actually gets to see the killer planting the breadcrumbs, although they might not realize what they are until they’re mentioned later, from a different point of view. This is something that you can play around with if you feel confident: how much are you giving away, and how? There’s even the crime-show motif of “we know who the killer is, now we have to prove it”, which means you have to have someone who can cover their tracks very well, and things that are very difficult to prove, like in the television show, Luther. Knowing and proving are different things, so that can be fun to play with, but requires very precise writing and planning.
The next step is one of the more fun steps: Who are you going to frame? You’ve got your misleading breadcrumbs, so they have to lead somewhere other than the killer, potentially. Whether someone is actually wrongfully arrested or the police just have a list of suspects to whittle through and someone looks uncommonly attractive, at least one red herring needs to muddy (or bloody?) the waters. If you’re going for an enclosed murder scene, like a boat or airplane, and “one of us is the killer” is your motif, then maybe you want multiple guests to look like equally promising killers. If you’ve got a more typical piece, maybe two or three people might fit the bill. In my Camp NaNo piece, I’ve got a handful of possible killers, but when I write murder mystery events, everybody’s got to have at least a small motive. Your needs will depend on your story.
Then, honestly, it’s just a question of writing the thing, weaving the plot and the breadcrumb dropping together. A little hint of this, a little smacking you over the head with a twist of that…. And then nuancing it in the editing process.
Editing is a really important part of writing a murder mystery, actually. If you have a couple of editors/friends read it and they all say either it’s too easy to tell who your killer is way too soon, or it’s absolutely and literally impossible to figure it out at all until the very end, you should listen to them. The worst thing a writer of mysteries can do is frustrated the reader with being overly obvious or impossible to deduce. If there’s a pattern, take the steps you can to fix it and toss it their way again. You’ll be glad you did.