(July 31, S.F. Chronicle. First letter from Zodiac):
This is the murderer of the 2 teenagers last Christmas at lake Herman and the girl on the fourth of July near the golf course in Vallejo. To prove I killed them I will state some facts which only I and the police know:
brand name of ammo, Super X; 10 shots were fired; the boy was on his back with his feet to the car; the girl was on her right side, feet to the west;
Fourth of July
Girl was wearing patterned slacks; the boy was also shot in the knee; brand name of the ammo used is Western.
Here is part of the cipher. The other two parts of this cipher are being mailed to the editors of the Vallejo Times and the SF examiner. I want you to print this cipher on the front page of your paper. In this cipher is my identity.
If you do not print this cipher by the afternoon of Friday the first, Aug ’69 I will go on a killing rampage Friday night.
(stop here?)*I will cruise around all weekend killing lame people in the night, then move on to kill again until I end up with a dozen people over the weekend.