Who do they think the Zodiac Killer was or is?

Answer 1

As is common with unsolved crimes, especially one like the Zodiac because of the public attention his crimes still get, it is difficult to get everyone on the same page. Which gives an indication of how hard this case was for the men and women that worked for years to bring about a solution, only to fail in the end. It seems everyone has an opinion and a favorite suspect.

That being said, the most likely person to have been the original Zodiac was Arthur Leigh Allen. Mistakes were made and opportunities lost in the early days and months of the investation and once that time is gone it is impossible to retrieve it again. The lead investigator Dave Toschi was certain that the Zodiac was Allen for a variety of reasons. He knew the case better than any other person with the exception of Robert Graysmith, whose decade long search for the answer ended right at Allen.