The Zodiac Killer. The two who survived his attacks gave the same exact description of him, as you can see. Yet he continued his spree, taunting the police and news with his own cypher, was never identified or caught. Now 50 years later only part of one of his cyphers has ever been decoded, and we are no closer to learning his true identity. His cunning, skill, and intelligence kept him from being known forever. He knew how to do it, when to do it, and where to do it, and get away with it. I greatly admire that.