Decaffeinated Corpse (Coffeehouse Mysteries, No. 5) by Cleo Coyle

Book #5 in New York Times bestselling author Cleo Coyle's Coffeehouse Mystery series...When an old friend of her ex-husband develops the world's first botanically decaffeinated coffee bean and smuggles it into the country, Clare Cosi, manager of Village Blend, believes it's a business opportunity she needs to investigate...at least until the first dead body shows up.