Robert Graysmith was a cartoonist at the San Francisco Chronicle while the Zodiac Killer was corresponding with the paper. He wrote the influential 1986 amateur investigation Zodiac (book), followed by Zodiac Unmasked (2002). In the first book he referred to suspect Arthur Leigh Allen under the pseudonym “Robert Hall Starr” to avoid litigation, later naming Allen directly. He estimated as many as 49 Zodiac victims.