The U.S. Attorney General (head of the Department of Justice) announced there were between 3 and 6 hijackers per plane.
One of the suspected hijackers had a disagreement about a restaurant bill in Florida, and said he could easily pay it because 'he was a pilot.'
At least two of the hijackers of the American 767 out of BOS supposedly flew into Logan Airport from Portland Maine (PWM?) on an American Eagle flight. Their luggage was not transfered in time to make the LAX-bound American flight. The luggage is providing useful information. Having arrived on a connecting flight, they likely would not have gone through a security checkpoint at BOS.