When Deborah Perez, a 47-year-old real-estate agent from Southern California, came forward this week with the claim that her adoptive father, Guy Ward Hendrickson, who died in 1981, was the infamous Zodiac killer responsible for five murders in the Bay Area during the late 1960s, it once again ignited the flame of controversy and speculation that has kept this case burning for decades. What’s even more remarkable was Perez’s assertion that she was present during at least one killing and even scribbled some of the taunting notes the Zodiac sent to the press and the police.

The Zodiac killer claimed to have killed thirty-seven people, but police consider five to be actual victims. He usually targeted young couples in secluded areas and killed them using both guns and knives. After each crime, the Zodiac wrote letters to local newspapers that sometimes included physical evidence from the crimes. He also sent four cryptograms to newspapers, but only one was decoded.

Police investigated over 2,500 potential suspects throughout the decades, including the Unabomber, Ted Kaczynski, yet the murders were never officially solved. There were a few suspects that stood out, but the forensic technology of the times was not advanced enough to nail any one of them conclusively.

The primary suspect was Arthur Leigh Allen, a child molester who died in 1992 at age 58 from failing health. Allen was fingerprinted, subjected to a polygraph, searched, interrogated, and induced to give handwriting samples. Still, there was no conclusive evidence implicating him in any of the murders.

The matter seemed settled until 1986 when author Robert Graysmith wrote his best seller ZODIAC, which concluded that Allen was the Zodiac killer. Now in its twenty-ninth printing, the novel was the source for the popular David Fincher movie released in 2007, which starred Mark Ruffalo, Robert Downey Jr., and Jake Gyllenhaal as Graysmith.

Police continued to investigate Allen a year before his death, although he protested his innocence. After his death, investigators even retrieved brain tissues for DNA testing. The technology at the time failed to prove anything.

Deborah Perez said she became aware of the Zodiac case in 2007, when she saw an episode about it on “America’s Most Wanted”, and started thinking that her father was involved.

San Francisco police said they would attempt to identify and if possible match the description given by Deborah Perez to the Zodiac killer.

Though many believe that Perez is lying and just trying to get publicity, she has passed psychological exams, and her handwriting samples have been confirmed by an “expert document examiner” from Los Angeles, who, coincidentally, is also an executive producer and narrator of a coming documentary about the case.