Mindhunter is a slow burn of a series, but that doesn't mean it isn't terrifying. Seasons one and two of the Netflix drama follow fictional FBI agents Holden Ford and Bill Tench — though they're inspired by real-life agents John E. Douglas and Robert K. Ressler — as they interview imprisoned serial killers around the country in the 1970s. Their efforts to understand what drives these violent criminals to murder are done to help build the FBI's fledgling Behavioral Sciences Unit and result in some deeply disturbing conversations.
Unlike Holden and Bill's characters, the serial killers featured in seasons one and two are very much based on real killers. The scenes featuring these infamous figures are chilling, to say the least. Actor Cameron Britton, who portrays Edmund "The Co-Ed Killer" Kemper, nails his role with startling accuracy, but he definitely isn't the only one. From Kemper to the BTK Killer to Charles Manson, read on to see each of these characters' horrifying ties to reality.