In the book ZODIAC UNMASKED, pages 446-453, Graysmith has several letters listed as Zodiac 'copycat' letters. I wonder if they were declared as forgeries by LE, or he determined that himself? Anyone know anymore about these letters? Maybe we can use the list to obtain more info thru FOIA requests. Here's the ones I found:
(some of these we may already be aware of)
12/7/69- Postmarked Fairfield, "I will kill again, I will turn myself in, okay"
10/17/70- Postmarked Berkeley, cut out of newspapers, " Monday October 12,zodiac is going to"
2/14/74- SLA letter. (cant figure why its listed by Graysmith as a copycat letter)
5/6/74-(2 days before the Badlands letter)sent to the Chronicle, marked as a 'postcard', Graysmith provides no addl info
10/29/87- "this is the Zodiac speaking, I am crackproof"