'We were there to serve Charlie,' recounts former Manson Family member Dianne Lake; he even asked her to bite off an umbilical cord when another girl gave birth.
A lot of it had to do with that well-honed 'Crazy Charlie' act.
The cult leader and mass murderer got parole hearings until the very end.
A 19th-century wife killer crafted poetic looking ciphers; a 21st-century serial child murderer used encrypted computer files.
Some have been broken, while others remain stubbornly resistant to code-crackers.
The elusive killer has never been found.
Here's why they were suspected—and why they were ruled out.