The Elements of Mystery Fiction: Writing the Modern Whodunit by William G. Tapply

five-foot) lawyers, and purple-haired (or skull-shaven) teenagers, or characters who are incredibly beautiful (or ugly), smart (or stupid), graceful (or awkward), do not strike the reader as true-to-life. At best, they’re utterly boring; at worst, they make the narrator or point-of-view character (and, by extension, the author) seem superficial and mean-spirited, and they will alienate rather than attract the reader.
    Complicated and interesting characters can be created with quick and simple strokes by giving readers something they don’t expect. For example:
    A janitor wearing a starched gray shirt and matching pants puttered nearby. He was pushing a big canvas basket on wheels. He bent close to me and emptied an ashtray into his basket. He was whistling softly.
    “ Pachelbel,” I said.
    He turned. “Huh? You talking to me?”
    “ The canon by Pachelbel,” I said. “It’s what you were whistling. Can I talk to you for a minute?”
     
    Major characters can—and should—be developed gradually. But writers need “tags”—quick, deft, unexpected strokes—to bring minor characters to life. A janitor who whistles classical tunes while he sweeps the floor, a beautiful actress who bites her fingernails, or a professor of Renaissance literature who carries a confession magazine under his arm will etch themselves indelibly in your readers’ memories.
    These characters are established and ready to be more fully exploited if and when you choose.
    Remember: In real life, we learn more about people through how they behave and talk than by how they look. How people appear, in fact, is often deceiving; the same is true of fictional characters. If you focus on your characters’ speech, mannerisms, actions, and responses to situations in the story, you won’t need to paint detailed physical descriptions of them or make them look strange for them to be memorable.
    Avoid the trap of telling readers what to think about a character. Instead of calling a cab driver “grouchy,” show him acting grouchy through what he says and how he behaves. Don’t call a woman “flirtatious”; instead, show her flirting with a man.
    Mystery readers want to figure it out for themselves, and they resent a writer’s depriving them of the opportunity to draw their own conclusions about characters. The writer’s golden rule—“Show, don’t tell”—is never more important than in creating interesting minor characters.
    Secondary characters play a limited but crucial role in your story’s development. You needed that whistling janitor to give your hero vital information, or to tell him the location of a businessman’s office, or to direct him to the fire escape. He’s a player. He might have a bit part, but without him the story will not work. He deserves your attention.
    Some minor characters, of course, are simply walk-ons. They are the bus drivers, ushers, clerks, waitresses, and others who anonymously populate your story. They serve a function, and should be thought of as objects rather than characters. If a bartender’s only function in your story is to deliver a drink, don’t describe him or give him dialogue. Just call him “the bartender,” as you’d call a passing vehicle “an automobile.” Characterizing him further is not playing fair. It intrudes on your narrative and distorts it by suggesting that the bartender might be more significant than he really is.
    Playing Mr. Potato Head
     
    When my children were little, they had a toy called Mr. Potato Head. It came with plastic noses, ears, mouths, hats, moustaches, hairpieces, and glasses that they’d mix and match, sticking them onto a potato to create a face.
    To create memorable minor characters, try playing Mr. Potato Head. Draw your characters from your experience. Mix and match the mannerisms, life experiences, and appearances of your friends and the people you encounter. Take note of how people around you act and react, speak and behave. Observe their table