Maybe I'm missing something, but how can this "copycat" letter be dismissed as "unrelated" to the real anthrax attack? If this was received on the same date the real anthrax letters where mailed, then how could the copycat copy something that wasn't yet made public?
Unless they had prior knowledge of what was going to be mailed from New Jersey a few days later.
The outbreak of anthrax, and death of Robert Stevens, at AMI preceded the hoax St. Petersburg letters. I wonder if the St. Petersburg mailer was a copycat to that event.
Even so, the selection of targets, letter style and such would point to some coordination with the New Jersey mailers, i.e. terror network, even though the St. Petersburg letters were a hoax.
In the hunt for the anthrax mailers, the St. Petersburg lead is not applicable. They should however be prosecuted - fiercely IMHO if indeed a part of a terror network.
If this was received on the same date the real anthrax letters where mailed...
The Daschle and Leahy letters were postmarked October 9, but the Brokaw and New York Post letters were postmarked on September 18 -- long before Troxler received his letter. As you mention, though, the information about the Brokaw and Post letters were not public at the time the Troxler letter was mailed. (I believe that information was put forth on October 11 or 12.)
Interestingly enough, originally the focus of the NBC case was on a letter postmarked from St. Petersburg on September 20. So it appears that there may be some connection between the two sets of letters (Trenton/anthrax and St. Pete/hoaxes). I'm not sure I believe there is a connection, but it would not surprise me to find out there is. The proximity of the postmarks (9/18 and 9/20, and 10/9 and 10/8 or 10/6) is certainly enough to pique my interest.
As I was typing this reply, I noticed you had posted again and said "Indeed, the St. Pete letter is outside the focus of this thread", but now that you have pointed out the possible connection, perhaps it is not outside the focus. I mean, if there is a connection between the two, the St. Pete letters might have an impact on the profile of the Trenton mailer.
Like I said, I'm not sure I tend to believe there is a connection, but then again...
The letter to Troxler was received on the same day the letters to Daschle and Leahy were mailed. But Bob Stevens of American Media had already died of anthrax (a week earlier, I think) by that date. It was already thought that American Media might have been sent the anthrax in a letter. And this was when there was a spate of letters with white powder that turned out to be hoaxes, many presumably by random copycats. (It's possible that the sender of the letter to Troxler was aware of the N.Y. Post letter and/or the Tom Brokaw letter, but I think it was a few days too early for that, if I remember correctly.)
I see nothing to connect this particular letter with the real anthrax letters. The handwriting is different (and looks American to me). The message in the letter was very different too. None of the real anthrax letters was from St. Petersburg (although I think other hoax letters were, including one to the N.Y. Times).
I think the only things that distinguish this hoax letter from others are that we have a photograph of the envelope and that the threat in the letter itself was memorable. It may also have been one of the earlier hoaxes.
I do think that it is possible that some of the letters with white powder that turned out not to be anthrax were mailed by the actual anthrax senders, to sow additional fear and uncertainty, and also to tie up investigative and medical resources on checking them out. It may also have been hoped that people would get complacent and end up ignoring suspicious letters.