The Zodiac Killer is perhaps the most infamous serial killer in American history and has been popularized by the major motion picture Zodiac, starring Jake Gyllenhaal. The Zodiac Killer, who operated in California in the 1960s-1970s, was confirmed to have killed 5 people, but could have possibly killed as many as 30. Aside from the horrific and grueling manner in which the murders were carried out, The Zodiac Killer literally made headlines, by sending letters to a number of San Francisco newspapers. He demanded that his letters be printed on the front page or he would go on a killing spree. In the letters, he referred to himself as “The Zodiac”, and included a cryptogram, saying once the cryptogram was cracked, they would have his identity. Although numerous professors and wannabe-cryptologists have tried to crack the code, numerous lines of it remain undeciphered and the true identity of The Zodiac Killer remains unknown.