Israel Keyes
Because it was asked for, here is a thread on Israel Keyes, but honestly, it’s kind of hard to explain all of the madness on here. This is why I think he’s the most prolific serial killer:
heroic French Air Force pilot during the Second World War, and a key subject in the non-fiction literary work Flight to Arras (Pilote de guerre) written by Antoine de Saint-Exupéry