The Zodiac Killer — California's Most Wanted

The Zodiac Killer was an unidentified serial killer who operated in Northern California during the late 1960s and early 1970s, claiming at least five confirmed victims and two survivors, though he claimed 37 murders in taunting letters to the press. He sent a series of cryptic ciphers to newspapers, three of which were not solved until 2021. The investigation produced numerous suspects over the decades — most prominently Arthur Leigh Allen — but no arrest was ever made. One of his four ciphers remains officially unsolved, and the case is considered one of the most compelling unsolved serial murder cases in American history.