Beautiful Sinner

FBI Special Agent Morgan Montgomery is having a really bad week, starting with her suspension from the Paranormal Crime Unit. To lick her wounds, she returns home to Seattle and tries to find comfort amidst family and friends. The memory of her mother's long-ago disappearance makes finding comfort harder than she thought.
When a daughter of the Royal Fairy Court turns up dead in an alley, Morgan goes against protocol and helps the local PCU team hunt down the killer before the fairy king takes matters into his own hands. Solving the case isn't as easy as Morgan expects, especially when bodies pile up and a mysterious demon starts doing his best to distract Morgan from finding the killer.
Morgan's past now intersects with her present as she works a mysterious case of demons, angels, and fairies. She must not only try to solve the murders; she must also stay out of reach of a demon doing his best to steal her heart-or possibly her soul.