When mystery authors create their stories, there's always an important balance they need to strike between developing the characters and setting so they're interesting, and making sure that the mystery is the focus of the novel. In a way, you could argue that that balance is more important in mysteries than it is in some other genres. After all, the mystery (whether it's a murder, a disappearance, or something else) is the main point of the novel. We mystery novelists want readers to try to figure out whodunit. We want the mystery to take center stage, or at least I do.
On the other hand, there is something to be said for fleshing out the characters, making the setting an important aspect of a novel, and in other ways giving a mystery novel life. In Janet Evanovich's Two for the Dough, Stephanie Plum is persuaded to buy a pair of beautiful but impractical high-heeled shoes. The shoes are mentioned a few times in the novel. They aren't at all central to the plot, they're not an important clue, and if Evanovich had chosen not to include them, the novel would still have been an engaging novel with plenty to keep the reader wanting more. But the shoes add some life; they give us an insight into Stephanie Plum's character. So does a scene in the same novel in which Plum encounters her ex-husband's mistress in a beauty parlor, and again in a department store. Those scenes aren't necessary to the plot. They don't give us a clue to the murder that's the central point of the book. But they do flesh out the novel and make Plum's character more real.
In Colin Dexter's Inspector Morse series, we learn that Detective Sergeant Lewis' favorite meal is eggs and chips. That fact is mentioned in several of the novels. It doesn't make the cases Morse and Lewis investigate any easier to investigate. It does, however, make Lewis more real. It's a small fact that makes us feel as though we know Lewis. That's one of the real advantages of adding some "window dressing" to a novel. Readers learn about the characters, perhaps identify with them, and want to know more about them.
In my own Joel Williams series, I face this balance all the time. On one hand, I want readers to get to know the characters and want to read more about them. They're people I know well and want to introduce to others. For example, a small fact about Williams that doesn't matter at all to the solving of any mystery is that he's got a dog - a mutt named Oscar that he inherited. Wiliams' friend and former boss, Bert Schneider has gone through a bitter divorce; his ex-wife made sure he has little "fun money." That fact doesn't change the outcome of any mystery. It does let us get to know Schneider a little. On the other hand, focusing too much on the characters and setting can take away from the mystery. That's been a major criticism of Lilian Jackson Braun's recent novels. We know so much about the denizens of Moose County that there's little focus on the mystery. I think about that when I write. I don't want to lose the sense of urgency that the focus on a mystery provides. At the same time, I don't want readers to have nothing to hold onto and look forward to for the next novel. It is a balance.
How do you feel about "window dressing?" Do you like to learn a lot about characters and setting? Do you prefer to go right to the mystery? Where is your balance?