Found hardcover mystery novel with blue cover

I found a hardcover mystery novel this afternoon around 3:15 pm behind the Salina Public Library on 7th Street in Salina, KS. It's a Penguin Classics edition with a bright blue cover, a slightly bent spine, and a dog-eared page near chapter 12. The back has a small red sticker that says 'Staff Pick' and a pencil note someone jotted in the margin. It seems well-loved but is missing its owner, and I figured someone might be searching for it, so I'm posting here in hopes of a quick reunion.