Detective Jo Martinez is a New York City native and one of the youngest officers of the New York Police Department to make homicide detective. Jo's sharp, no-nonsense instincts and her ability to close difficult cases have given her a tough-as-nails reputation on the force, despite also dealing with the untimely loss of her husband. Working with Dr. Henry Morgan was initially a challenge for Jo, but over time the investigator has come to appreciate Henry's annoyingly creative approach to solving homicides. Combined with Jo's quick-fire cop instincts, Henry's deductive talents have not only contributed to a successful partnership, but also to a budding friendship.