Dan Koh looks at one of the most famous unsolved murder mysteries in history: The Zodiac Killer. Often compared to Jack the Ripper, the Zodiac Killer hunted his victims indiscriminately, with little obvious connections between them. He even taunted the police, leaving coded messages and giving clues that only the murderer could know. Fifty years later, his final code was cracked. But was it enough to reveal his identity?