Shop Till You Drop by Elaine Viets

Helen works at Juliana’s in South Florida. It’s a job with absolutely no prospects, but it’s the type of job that Helen wants and needs. She had to quickly leave her old life behind in St. Louis, and now she is stuck taking sub-par jobs to avoid her past catching up with her. In spite of terrible customers, a boss with questionable morals, and poor pay, Helen makes it work until the day a dead body is found in a barrel in Biscayne Bay. When the police start to investigate, the clues lead to Juliana’s and its staff. Helen is suspected of murder. In order to clear her name, she starts her own investigation.

With a quirky cast of characters, Shop Till You Drop draws the reader in. There are enough suspects to keep you guessing until the closing chapters of the book, and the novel concludes nicely with an epilogue that explains what happens to all the players involved. This is the first book in the "Dead-End Job Mystery" series, so there are plenty more dead-end jobs for Helen if you are interested in reading more.