Primal Instinct by Janie Crouch

A killer stalks the city streets, and one FBI agent is determined to bring him down in Janie Crouch's Primal Instinct. 

On the crowded streets of San Francisco, a serial killer watches and waits. Known only as "Simon Says," he lures his next victim while the FBI grasps for answers. Desperate, they turn to Adrienne Jeffries. Adrienne has an uncanny talent for getting inside the city's most dangerous minds. But first she'll have to get past FBI agent Conner Perigo. Skeptical of Adrienne's abilities, Conner begrudgingly enlists her help…unprepared for the powerful attraction that could jeopardize their focus. With little time, and everything to lose, they must work to find Simon's next victim–before he does.