"It’s probably the greatest American unsolved serial killing case. Sullivan also bears a striking resemblance to a police sketch of the Zodiac Killer released at the time. "That letter was very similar to ones the Zodiac sent -- so much so that he misused and misspelled the same letters," Mains said. The Zodiac, Mains noted, sent encrypted communication to area newspapers divulging intimate knowledge of the murders. "It’s probably the greatest American unsolved serial killing case," Mains said.

Source: Fox News December 01, 2017 17:26 UTC