When No One Is Watching (Harlequin Romantic Suspense Series #1818)

The red-hot passion between them isn't exactly an open-and-shut case… 

To find her missing sister and an attacker she can't remember, criminal profiler Mia Perez teams up with gorgeous Boston P.D. lieutenant Gray Bartlett. Their prime suspect: a psychotic serial killer. But when Mia's prints are found on the gun used in recent murders, Gray doesn't know what to think. Is the brainy beauty he's falling for being framed? 

Mia finds herself incredibly attracted to the hero risking his life and career to protect her. Yet she keeps a deadly secret of her past from Gray. Now she needs more than his desire—she needs him to prove her innocence, find her sister…and keep her alive.