Supporting characters are rich tools for misdirecting your sleuth. Characters because of their secrets, lies, and coverups lead the sleuth down trails that are dead ends.

When you observe people, you’ll notice actions and dialogue that you can use in your mystery. Keep them in your notebook, because there are ways to make your innocent supporting characters look guilty.

Obvious Motive – the character inherits the estate, or business or wanted the victim as a partner or was being blackmailed by victim or had been jilted by the victim. 

Vanishing Act – the character can’t be found when the sleuth comes to question him. He may be innocently off on vacation or a business trip or a romantic tryst. Because your investigator can’t find him, he’ll appear to be deliberately avoiding contact.

Stonewalling – the character can’t remember or refuses to tell where they were at the time of the murder. 

Contradictory Behavior – A character who claims to be clueless about guns has an NRA membership card in his wallet, a character who claims to have been in love with the victim was having an affair with someone else.

Eavesdropper – the character is overheard telling the victim “drop dead” or threatening the victim. 

Emnity – the character hates the victim. They may be  business rivals involved in a nasty lawsuit or the victim stole their spouse away.

Overeager - the character goes to the investigator and provides tons of information that implicates someone else. But, only some of the information turns out to be true.

Bad Reputation – the character is known to be a liar, or a swindler, cheats on girlfriends, deals drugs, etc. 

Guilt by Association – the character hangs out with unpleasant or unsavory characters or is married to someone who hated the victim.

Previously Suspected – the character was convicted of a similar crime though he always claims he was innocent.

Skeleton in the Closet – no one knows it but the character was once or still is a compulsive gambler, pedophile, alcoholic, drug addict, etc.

Crack in the Veneer – a kind, generous, flawlessly beautiful character, kicks a dog, slaps a child, or grinds an expensive piece of jewellery under his heel. Any action that seems completely out of character.

With these as starters you need to give the characters a secret and the lies they tell to cover up their secret. Building on secrets creates puzzles for your reader and sleuth to solve. Done well, the sleuth will solve the puzzle before the reader.

Zara Altair
 Zara Altair writes traditional mysteries set in the time of Ostrogoth Rule in Italy in The Argolicus Mysteries. She coaches writers on story, especially mysteries.