In any successful novel, the hero is the star of the story, but it's the lesser characters--the second bananas--who carry the show. As a reader I get annoyed by stories that feature secondary characters who are limp or cardboard: The "blond, leggy" girl who is tossed in for a smidgen of sexual tension; the "beefy cop" who turns up at a crime scene; the "tired-looking" hotel clerk. At these moments it's like the writer is screaming to the reader, "Hey, I need to include this character to move the scene forward, but don't bother paying attention to him."
All secondary characters, major or minor, need to live and breathe for the reader. In his book On Writing, Stephen King said that every character in a book thinks of himself or herself as the main character. Whenever that character is on stage, even briefly, he should be presented as if a spotlight is shining on him.
During a radio interview about my latest book, Makeovers Can Be Murder, the host asked me questions about a couple of the minor characters in the story. One of the characters had two walk-on appearances in the book; the other guy you never even saw, just heard him referred to. And yet the host had a sense of them, was drawn in enough to speculate about their motivations. I felt happy about that, like I'd done my job as a writer.
When I think of strong secondary characters, a few standouts come to mind: Dill in To Kill A Mockingbird; Melanie in Gone with the Wind; the wealthy, pompous Lady Catherine De Bourgh in Pride and Prejudice.
Which secondary characters are the most memorable for you in thrillers or mysteries? (Other than Dr. Watson--too easy.) Do you think most authors in the genre do a good job or a poor job or portraying second bananas?