The very first indicator is the hand writing. Unless someone has extensive training in hand writing analysis(which of course, could not be totally eliminated as a possibility) how someone learns language is very difficult to mask. The typical American printing is much different than the typical arabic printing. American printing tends to be block letters (such as were contained in the letters). Arabic printing tends to have lots of serifs (curley letters). American printing tends to have a forward slant (such as were contained in the letters). Arabic printing tends to have a backward slant, because they learn writing from right to left instead of left to right.
A very strong indicator that points to a deranged individual rather than a state or a well financed organization is simply the total amount of anthrax. The entire amount added up to no more than a few ounces. Iraq has tons of the stuff, they more likely would have put it in thousands of pieces of mail instead of just a few. It appears to be the product of a very bright individual working with very limited resources.
Another indicator is the timing. The earliest date of cancelation was about a week after 9/11. This points to someone who did not know 9/11 was going to happen, but saw it as an opportunity to hide their own tracks.
These are the normal operating perameters.
You replied:
The very first indicator is the hand writing. Unless someone has extensive training in hand writing analysis(which of course, could not be totally eliminated as a possibility) how someone learns language is very difficult to mask. The typical American printing is much different than the typical arabic printing. American printing tends to be block letters (such as were contained in the letters). Arabic printing tends to have lots of serifs (curley letters). American printing tends to have a forward slant (such as were contained in the letters). Arabic printing tends to have a backward slant, because they learn writing from right to left instead of left to right.
Handwriting is notoriously difficult to analyze, especially such short samples. But others have suggested that the handwriting actually shows a similarity to Arabic script, in particular the way the E in Israel is formed in the Post/Brokaw letter. See this posting by Nogbad and this follow-up.
A very strong indicator that points to a deranged individual rather than a state or a well financed organization is simply the total amount of anthrax. The entire amount added up to no more than a few ounces. Iraq has tons of the stuff, they more likely would have put it in thousands of pieces of mail instead of just a few. It appears to be the product of a very bright individual working with very limited resources.
Even an individual could have used this quantity of anthrax to murder thousands, by releasing it in public places. Instead, the sender chose to mail the anthrax to a small number of individuals, with warnings. This only makes sense if it was intended to have the effect of military deterrence; it makes no sense as an actual attack of any sort.
Another indicator is the timing. The earliest date of cancelation was about a week after 9/11. This points to someone who did not know 9/11 was going to happen, but saw it as an opportunity to hide their own tracks.
You mean some nut was sitting on a vial of anthrax, all ready to go and just waiting for a major terrorist attack so he could take action under cover? That's not very plausible.
There's really no evidence pointing to a domestic origin for the anthrax attack. See Thud's excellent summary of the why the evidence points to a foreign source; I added a few points in this follow-up.