I'd like to know if they had the box cutters with them when they went through security - and security saw them and still let them through - or if it was an inside job, that the box cutters were placed under their seats for them.
Boxcutters were OK to carry on board pre 9/11.
Jayna Davis's book has some strong clues in it as to what the answers may be to how the box cutters got on the flight.