The principle suspect in both the book Zodiac and its film adaptation of the same name, Zodiac (2007 Fincher), Arthur Leigh Allen, was heavily implicated as the Zodiac Killer. The film’s closing credits make note that Allen may have been exonerated by a partial DNA mismatch. I’ve linked a story from the San Francisco Weekly disputing this story.
It is also worth noting that the handwriting matches which helped stop the investigation into Allen, courts of law have been mixed as to whether handwriting analysis can be considered as substantial evidence. I’ve linked an interesting article discussing this.
I’ve embedded a series of interviews concerning him from the Special Edition of the film Zodiac. As a forewarning, I found this a bit disturbing. The descriptions are at times graphic.
In Defense of Arthur Leigh Allen, there is no clear evidence he is guilty. The most important thing to remember when discussing whether Arthur Leigh Allen is that all evidence against him is purely circumstantial.
I’ve linked to stories with several other potential suspects:
George Russell Tucker: https://blog.sfgate.com/crime/2012/05/14/ex-gumshoes-zodiac-book-fingers-solano-county-man/
Louis Joseph Meyers: http://abc7news.com/archive/9441384/
For even more, visit: http://zodiackiller.com/index.htm
All-in-all, I doubt the Zodiac killings will ever be solved definitively. I’ve attached a sketch artist’s sketch of the Zodiac Killer and a picture of Arthur Leigh Allen to help you draw your own conclusions.
To help you draw better conclusions, I’ve attached compelling evidence that Ted Cruz is the Zodiac Killer.
As a final note, the misspellings and strange grammar in the Zodiac’s cryptogram are not unusual as is shown by the Kryptos Sculpture at the CIA’s headquarters. https://www.cia.gov/about-cia/headquarters-tour/kryptos