Character is how you develop through your life experiences. The dictionary definition is the mental and moral qualities distinctive to an individual.
A character is also a person in a novel or play or film.
The one impacts on the other.
When you create the characters in your crime novel, obviously, the ones who will occupy most of your interest are your main character (Protagonist) and the killer (Antagonist).
These two characters may often be very similar in character. In other words, they may be aiming for the same prize but what that prize is, will be altered by their mental and moral qualities.
Your protagonist will not be all good, just as your antagonist will not be all bad. Everybody, even serial killers, have good and bad qualities and your writing will be much richer is you exploit this.
Your protagonist wants to catch the killer. The killer does not want to be caught. Killers in crime novels are frequently portrayed as being so arrogant they think they will never be caught, but just as your killer is a human being, he or she will have doubts and be indecisive just as we all are.
Your protagonist may also be arrogant enough to think he or she will catch the killer, but, unless they are the boring stereotypical flawed drunk with inner demons and everyone’s hand turned against them — how boring that trope has become — the one difference will be that your protagonist will have an ally who supports them. That could be a murder squad if you are writing a police procedural or a close friend/partner who acts as a sounding board for your amateur sleuth and helps them clarify their thinking.
By contrast, unless the murder(s) are a joint enterprise, your killer will only have him or herself to talk to and that may well increase their arrogance and certainty.
But what about the other characters? You must have a big enough ‘stable’ of characters in your novel to make the mystery a mystery. And remember that one of Agatha Christie’s main strengths was that all her books have a huge range of characters. That gave her so much leeway to seed clues and red herrings aplenty and lead us down a usually very winding garden path.
Think of five friends. They will all have differing characteristics because they will all have had differing life experiences.
Joanna might have been raped by her stepfather, was too frightened to tell anyone, so never gained justice. That experience will have coloured her view of men. She may shun relationships or, worse, she may have a behavioural habit of choosing controlling, abusive men because her self-worth is under the floorboards - like her husband might be if she suddenly snaps.
Now compare Joanna to Rebecca, whose upbringing was sunny and secure and whose parents encouraged her to be happy. Rebecca will be as different in character as chalk is to cheese, because she has not had Joanna’s experiences. But does that make Rebecca ripe for being a victim because she will automatically be more trusting?
What about Tom? He’s working for his dad in the family firm of builders. Tom was brought up to think there was no alternative, but his one desire is to go to art school and paint. He earns good money but spends it to compensate for not being what he wants to be.
Compare Tom to Ian, whose father walked out when Ian was three and his baby sister was just turned one. Dad told Ian that he must now be the man of the family.
Tom might be resentful but unable to break away from the security of a good family and a steady income. Ian has been hustling to help his mother since before he went to school. He worked three jobs. A paper round, helping people with their gardens and walking neighbours’ dogs. You might presume Ian is more likely to succumb to the lure of earning easy money by working for the local drug lord
And then we throw in the what-if? How would knowing Tom and Ian's characters affect your novel if you turned that presumption on its head and made Tom the drug runner because he wants to salt enough money away to go to art school while not giving up being able to spend his earnings?
I would counsel not creating your characters to fit your plot. There will always be something off kilter with the resulting book. There are hundreds, if not thousands, of crib sheets for creating characters, some of which go to ridiculous lengths in terms of what your character eats, hates etc.
Why do I think that is overkill? Because, in truth, our likes and dislikes in terms of colours won’t affect the story one iota - unless the character is colour-blind. All it will do is confuse you, the writer, because you will have spent so much time making everyone completely different, you will feel a need to include all of it in the book.
If you decide one of your characters is allergic to shellfish, that food preference may be relevant as a clue or a red herring. But knowing that Greg likes steak but hates lamb is meaningless unless it has a purpose in the book. Don’t bog yourself down.
Think of the 2 most popular detectives in the last 140 years. Christie’s Poirot and Conan Doyle’s Sherlock Holmes. What do we know and what do we need to know about each?
We know Poirot is egg-shaped, vain, fussy, and meticulous. We have no idea what colours he likes or dislikes or even his food choices because those are irrelevant to the stories.
There is nowhere in the Poirot stories where he says ‘Look at that woman in the red dress, Hastings. She must be guilty because I abhor red.’ No. He might say ‘Look at that woman in the red dress, Hastings. See how she looks around. I wonder why her hand is in her pocket.’
Similarly, we know that Holmes is tall, fit, vain and smokes a lot. Conan Doyle sees Holmes as a machine so the reader couldn’t give a Flying Fortress whether he likes dogs or cats. We don’t need to know it.
I am a visual writer so like to find pictures that fit the character in my mind’s eye. For example, in The Tudor Enigma books, my protagonist, apothecary, Luke Ballard, looks like a younger William Petersen, who played Grissom in CSI. The minute I saw one particular picture, I knew just what Luke Ballard was like as a person.
Try it. Let’s say you want a man in his 20s who is a bit of a flirt, a charmer, but who has a look in his eye that says he uses it for his own ends. Keep those characteristics in mind. A charmer with a nasty edge. Now go into your preferred search engine and check out images of men in their 20s. It may take some time but one may well just pop off the screen. That’s what your character looks like.
Look again. What can you imagine him doing? Would he kill someone without a second thought? Would he go to Africa and build schools for children? Could he be one of twins? Plenty of playing room for creating havoc in your story with that one.
Once you know the essence of your character, you have something to build on. What does it matter what he wears or what toothpaste he uses unless the events in your story demand we know he would never use whitening toothpaste? And if he is the victim, why was whitening toothpaste found in his hotel bathroom?
When you have enough characters to people your story, start thinking about how their characteristics will impact on your basic plot. You will find that they affect it greatly and sometimes they can send you in a totally different direction. In Long Shadows, I have one character who made an unplanned declaration of love. Not only had he not planned it, neither had I. But, knowing what he was like—his characteristics—I knew exactly what new path I could make him tread and it strengthened the book. Long Shadows is due out shortly.
Last words. Don’t hurry your characters into the world. Let them stay by your side as you walk the dog, cook dinner or cut the lawn. Let them talk to you as you wander around the supermarket. When you know them and you know the bones of your plot, you can create a compelling story.