21Ed Kemper
At the age of 15, Ed Kemper murdered his paternal grandparents. After he came out on parole at the age of 21, he went on to kill six college students, his mother and her best friend. He was also a prolific audiobook narrator and he has several hundred completed recordings to his name. He once buried one of his victim's severed head in his mother's garden as a joke and later remarked that his mother “always wanted people to look up to her.” On one occasion, when he was left alone in a cell with FBI agent Robert Ressler, who was interviewing him, Ed started taunting him, implying that he was going to murder him. Once the guards returned, Ed told Ressler that he was "just kidding."
22Ted Bundy
Ted Bundy helped in the investigation of the green river killer and made a psych profile which ended up being closer to the actual green river killer than the FBI's own psych profile. That was also a huge part of the inspiration for the silence of the lambs. Bundy also tried to masturbate to photos of his crime scene when detective Kepple brought them in, which is why they stopped letting Bundy keep the files.
