Im trying to decipher each letter or string of letters from the zodiackillerciphers.com/wiki/images/7/7d/340-cipher-hi-resolution.jpg letter. I just started so i've only done the first few, but what i notice is that the reverse semi-square symbol which is the 4th one in the letter strangely resembles the murder locations.

And also, looking from the zodiac killer's symbol which is basically two lines, one on the horizontal axis and one on the verticle with a circle in the middle, it kind of resembles the Earth symbol in astrology, i'm going to sleep now, just the first few symbols were hard work, don't even now if thats what he meant as of their meaning. Im fascinated by him.