Please be more clear; I don't understand what you are saying in your second sentence. Thanks.
It's a bit complex, but the main idea is all the anthrax envelopes were mailed in S. Florida by a single individual.
That individual placed each envelope in a different collection box.
This was a wealthy neighborhood full of rich retirees with loud mouths. USPS regularly puts extra collection boxes in such places just to shut them up (handling complaints costs lots of money).
Little mail originates in these places. When the hijacker dropped a letter into the box it fell into a standard flat tray. (There are letter trays and flat trays. One is for letters and the other is for flats - large envelopes and magazines are called flats.)
The collection driver simply pulls the trays from the collection box and replaces each with a new empty tray. He stacks the trays up in his vehicle. Since they have only 1 letter in them, these trays are readily misidentified as empty equipment, or MTE.
Empty equipment from S. Florida is regularly sent to Philadelphia BMC. It is distributed from there to postal facilities in New Jersey and Eastern Pennsylvania.
There's more to it, but it would have been strange to have these letters show up anywhere else but New Jersey!
A Postal Inspector nearly died of anthrax due to complications which were clearly covered in Ken's book. The CDC didn't bother to advise the doctors caring for the Inspector of what was known about the progression of inhalation anthrax. The FBI apparantly hadn't bothered to consult with the CDC either.
A big problem here is that these various federal agencies have top managers who are too brain dead to realize that there is expertise elsewhere.
This might well have something to do with the salarycap on federal employment plus the need for federal managers to be first-class a$$ki$$ers even if this is a dangerous practice which may destroy the Republic.
9/11 demonstrates why our federales have got to be smarter and tougher than the gang we have presently.