Robert Graysmith was a cartoonist for the San Francisco Chronicle when the newspaper began receiving letters from the Zodiac, the mysterious serial killer who plagued the Bay Area for several years in the late 1960s and early 1970s and then disappeared. Police confirm at least seven victims of the Zodiac's attacks, but in his letters he claimed responsibility for many more. Graysmith became obsessed with the macabre details of the case: the Zodiac's taunting letters and ciphers claiming to contain his name, the map with the Zodiac's signature mark over Mt. Diablo, and of course the vicious and bizarre nature of the murders themselves. In ZODIAC, his bestselling account of the murders, Graysmith places the many grisly elements of the case into a clear and riveting narrative, and even describes the man he considers to be the true killer. In 2007 the book became the basis for the film ZODIAC directed by David Fincher and starring Jake Gyllenhaal as Graysmith.