Somebody I used to know / David Bell.

"When Nick Hansen sees the young woman at the grocery store, his heart stops. She is the spitting image of his college girlfriend, Marissa Minor, who died in a campus house fire twenty years earlier. But when Nick tries to speak to her, she acts skittish and rushes off. The next morning the police show up at Nick's house and show him a photo of the woman from the store. She's been found dead, murdered in a local motel, with Nick's name and address on a piece of paper in her pocket. Convinced there's a connection between the two women, Nick enlists the help of his college friend Laurel Davidson to investigate the events leading up to the night of Marissa's death. But the young woman's murder is only the beginning .and the truths Nick uncovers may make him wish he never doubted the lies"--