In Netflix's Mindhunter, the serial killer interviewed and played by Cameron Britton is Edmund Kemper.
Kemper, known as the Co-ed Killer, became one of the first notorious prisoners interviewed by FBI agents Holden Ford and Bill Tench in the series. His extraordinary height, calm manner, articulate speech, and willingness to discuss his crimes make his scenes among the show's most unsettling. The interviews are used by the fictionalized FBI team to develop ideas about criminal psychology and behavioral profiling.
Cameron Britton portrays Kemper in the first season and returns for an appearance in the second. His performance earned a Primetime Emmy nomination for Outstanding Guest Actor in a Drama Series. Britton's portrayal emphasizes Kemper's conversational intelligence without treating him as a reliable or sympathetic narrator.
The other options are also real serial killers, but they are not the character Britton plays in Mindhunter. John Wayne Gacy, Jeffrey Dahmer, and Ted Bundy belong to the same broad subject matter, which is why they can seem plausible in a question about the show's interviews.