The Zodiac Killer

By August, no fewer than four experts, including Keith Woodward, former chief of the LAPD's document department; Robert Prouty, the specialist bypassed by Toschi in April; his BCII colleague Terrence Pascoe; and John Shimoda, the Postal Service expert who had initially confirmed the letter; had determined that the April letter was a fake, "a carefully drawn copy of the true Zodiac printing .... constructed by a person that had access to printed letters of the Zodiac".¹  The lone holdout to this finding was the retired Sherwood Morrill, whose bitter statements to the media revealed a determined loyalty to Toschi and a great disrespect for Gain. The letter of January 1974, which had also fallen under suspicion, was deemed to be genuine.

Speculation as to the author of the 1978 letter has focused on three possibilities.  The first, of course, is the Zodiac himself, though even the untrained eye can see that the words and characters seem to have been meticulously drawn rather than written in the semi-manic freehand used by the killer in his earlier missives.

Second is Toschi, and rumors have even suggested that he was identified as the author by DNA testing in the 1990s, though there have certainly been no official pronouncements to that effect by the SFPD or any other source.  An FBI memo from August 1978 states that analysis of the April letter was discontinued "in light of recent disclosures ... indicating that David Toschi had authored one or more 'Zodiac' letters" ² though it must be remembered that the FBI received this indication from the SFPD, and not through its own investigation.  In fact, Toschi was eventually reinstated to his post as a homicide Inspector.  

Finally, author Robert Graysmith had enough knowledge of the Zodiac literature to forge such a letter, and even had a motive -- he had been shopping his novel about the case for two years already in 1978, though it would not see print until nine years later.  In this book, Graysmith describes a photo enlarger setup that he claims could have been used to write the original Zodiac letters, but would have served quite well to forge the latest one.  It may be worth mentioning at this point that Graysmith had been disciplined for plagiarism during his time as a cartoonist for the Chronicle.  In any event, he has lobbied quite vocally on Toschi's behalf, maintaining in his book and in subsequent interviews that, whoever wrote the letter, it wasn't Toschi.  San Francisco Police remain tightlipped on the issue, saying in 1999 that "The Police Department has never made a statement on [accusations that Toschi faked a Zodiac letter] one way or another.  We will confirm that not all the Zodiac letters are authentic". ³