A Whisper in the Dark — Linda Castillo

Until now, no one has suspected the truth about down-to-earth bookseller Julia Wainwright. But the arrival of six threatening letters indicates someone has discovered her secret -- and wants her to pay for her sins...

Ever since he accidentally killed a fellow cop, John Merrick has been tormented by the mistakes of his past. Now, called upon to repay a favor, he will do anything to keep Julia Wainwright safe. To do that, though, he'll first have to figure out what the gypsy-eyed beauty is hiding...

As the threats escalate, Julia and John must find a way to trust each other. Because if they don't, a twisted stalker will make sure all the gruesome things he's promised will come true...