Bone Harvest — Mary Logue

When a quantity of dangerous pesticides is stolen from a local co-op in Pepin County, Wisconsin, Deputy Sheriff Claire Watkins is called in to investigate. The thief has left one bizarre clue: the finger bone of a child long dead. The pesticides soon reappear in flower beds, in animal feed, and in a fatal concoction at a Fourth of July picnic. Each time, a tiny human bone is left at the scene. With the help of a quirky aging newspaper editor, Claire unravels the secrets of the past, leading her to a pair of young lovers, a man enraged over his mother's death, an obsessive recluse, and an unsolved murder case half a century old. Claire desperately races against time to find the madman before he uses the lethal pesticides again. But he won't be stopped until he gets what he wants.