First Appearance: Glory in Death
Temporary aide in Glory and Immortal in Death
Permanent aide: from Rapture in Death through to Imitation
Partner: Promotion to Detective, third grade in Imitation in Death.
Delia comes from a family of "Free-agers" , which is a fictional extension of the New Age movement from the 1980s. Her family is very peaceful and pacifistic, but Delia prefers exercising justice her way - the police way. She is a very responsible and sober police officer, but as the books continue, her personality relaxes. She dates Charles Monroe for a little while starting in Holiday in Death, but she quickly realizes that she thinks of him as a brother. Nevertheless, they continue to go out on excursions together, confusing Ian McNab.
Ian McNab is Delia's lover; she meets and clashes with him in his introduction during Vengeance in Death. They start a sexual relationship in Loyalty in Death, break them off in Betrayal in Death, and officially start dating in Seduction in Death. He meets her parents in Reunion in Death, they move in together and sign a lease in Visions in Death, and she visits his family in Memory in Death (they live in Scotland). She's very happy with him, but as she states to Eve once, she's fine living with him - marriage is verar off.
Eve tells Delia about her childhood and subsequent act of patricide in Visions in Death.