Shattered Souls by Karen Kelley

New Orleans, a town filled with history, a melting pot of cultures… and a satanic serial killer.

FBI agent Natalie Collier, an expert on the occult, has returned to Louisiana to help catch a serial killer, not have an affair, but Detective Tate Ellis is tempting. Until he starts asking too many questions about a past she would just as soon stay buried. Natalie wants to catch this guy, then get the hell back to Texas, but she soon learns the past has a way of overlapping the future, and sometimes there’s no escaping it.
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Detective Tate Ellis is intrigued. What kind of woman can pick a lock, hotwire a car quicker than he can put in a key and start it, and steal your wallet all the time she’s smiling at you? And she’s hot. Natalie is the type of woman who can make a dead man sit up and take notice when she walks by.
Yeah, Natalie puzzles him. She’s good. Damn good. There’s no doubt about that as he watches her ferret out the smallest clues about the killer. But there’s something she’s not telling him. She has secrets, and a deep pain reflected in her eyes that she can’t quite hide. Who hurt her? And will she let him get close enough to heal her wounds?