Down in Boca Raton they had been dropped in collection boxes in a wealthy neighborhood. Ordinarily these boxes receive little or no mail, but they are watched closely by retired coupon clippers who are always ready, willing and able to file a complaint.
Atta, et al, dropped the envelopes into such boxes. At that point in the cycle the tape on the envelopes was still working and the anthrax had not yet penetrated the paper. Odds are no contamination whatsoever was left behind on the collection boxes, whether on the lid, or inside. In any case, all of these collection boxes have a flat tray on the inside. Whatever mail is dropped in is collected in the flat tray. One letter drops in - it goes in the tray.
When the boxes are pulled for collection, the normal course is to pull the tray out, look to see if any mail fell behind the tray, and then put the tray into the collection vehicle. A new but empty tray is then placed into the collection box which is then closed and locked.
At the end of the route all the trays full of mail are set on the carrier apron or on the acceptance and/or dispatch platform. Given that the area where these envelopes were placed was repleat with watching wealthy and elderly people, the collection employees have learned very well how to avoid complaints and criticism.
Accordingly he or she stacked up all the trays collected and placed them on the platform together. Unfortunately (but, as usual) the trays were mistaken for empty equipment. Typically the collection boxes would be only lightly used anyway if this happened on a Saturday afternoon, that is September 8, 2001.
Saturday evening operations are light, and the next step for these apparantly empty trays was for them to be placed on a pallet with a number of others, get shrink wrapped, and then dispatched NORTH to a BMC or other facility which would then route them to MPCs and AOs for use.
These trays could also be routed directly to Jacksonville or Greensboro BMCs for delivery on to a major mailer, or redirect to yet another BMC. As I recall South Florida empty equipment is frequently returned directly to Philadelphia BMC (in short, on a return trip on vans pulled by tractors already contracted to make the Philadelphia to S. Florida standard mail runs.) (It can be much more complex than this, of course.)
Remember that under this scenario these envelopes are snug and secure in the bottom of flat trays with yet another flat tray inserted as a plug. They are further encased in shrink wrap. The anthrax spores have not yet penetrated the paper (although that will certainly happen within 2 weeks - we know that because it did!).
Wherever these trays go, the mailer or other user will begin working them down from the top. Since these letters were postmarked in 010, we must presume that the USPS employee or mailer employee who grabs the tray to use it sees the letter, recognizes that it is a piece of FCM and tosses it over to a tray being routed to a preferential mail operation. Remember, too, flat trays are for flats and letter trays are for letters. A letter in a flat tray is a mistake. This time the mistake was corrected.
The large commercial mailer that could have been the destination point for these letters was one of 8 in the Trenton area. Someone should check them all out for signs of anthrax contamination. Or, maybe the trays were put into service right there in Trenton. We know where the contamination is there. Did they check the trays? Probably not! That's how the folks in NY and CT got infected - by the time these trays were emptied in NJ they had been contaminated, and if they were then filled with other mail, it too would be contaminated. Notice that the very next person infected with anthrax was a letter carrier there in New Jersey. It is normal to take mail out to the carrier apron in a flat tray! It takes but seconds to demonstrate how a flat tray works as an atomiser.
So, the issue now is why the Philadelphia BMC showed no contamination? Well, the answer is none of the anthrax got loose from the envelopes as they passed through Phily BMC - they were wrapped exceedingly well, and the polywrap the USPS is not only strong, it can create an airtight surface.
Is there another objection to my scenario which has the pieces mailed in Boca Raton, the only place yet to show contamination of any mail acceptance equipment, and yet be canceled in New Jersey?
There's one thing I don't understand. Why does the USPS shrink-wrap stacks of empty trays?
If, as in your theory, the anthrax letters were actucally mailed from Boca Raton, but were accidentially transported to New Jersey where they were cancelled and sent on for delivery, isn't it too much of a coincidence that the terrorist thought to write a New Jersey return address on the envelope?
I'm not sure I buy it.