"But Moussaoui is no longer believed to be a 20th hijacker, and the government deleted references to his interest in crop-dusters from its indictment."
This sentence is innocently misleading. The govt. deleted the reference to crop dusters very early to build the case he was the "20th hijacker."
Besides Mous. there were reports of Atta and cohort visiting cropdusters in Florida.
Wouldn't want to remind folks about something that might raise disturbing questions.