I never knew this at the time but as it turned out the Anthrax was most likely released by a military scientist, Bruce Irvins, who worked on Anthrax vaccines. He feared that his life's work was being defunded, so he contrived an Anthrax crisis to give it fresh attention. He committed suicide when he became a suspect so we never got a confession but that was the FBI's working theory. A bioweapon false flag to increase biodefense funding.
And the craziest part was, he succeeded in his goal. After the crisis, the NIH 30xed the budget for Anthrax biodefense.