Colleen Hatteras is a volunteer genealogical researcher with the Open/Unsolved unit of LAPD. Her supervisor is Renee Ballard. In 2024 Hatteras was assisting in the investigation into the Pillowcase Rapist. Old DNA evidence indicated that the prime suspect was the unidentified father of Nicholas Purcell. Ballard's work discovered that Purcell was adopted through unusual procedures, and the identity of Purcell's biological father was unknown. Hatteras and Ballard were able to target Andy Bennett as Purcell's biological father.
As a volunteer employee, Hatteras was somewhat annoying. She had difficulty limiting her attention to her assigned work, and she expressed the desire to get more involved in real police work. Ballard was able to keep Hatteras under control most of the time, but in the Bennett case Hatteras made the very unwise decision to act on her own. She contacted Bennett directly, raising his suspicions. He tracked her to her home and strangled her in a futile effort to avoid prosecution for his past rapes.