The FBI investigates crimes.

Petraeus' "Biographer" (i.e. girlfriend) lived on base in Afganistan for the year Petraeus lived at the same base.

The questions are, did his girlfriend (knowingly or not) meet/give her email to/talk online with, contacts while in Afganistan of the Taliban/Al Quieda?

There's little doubt that Petraeus & his girlfriend were emailing back and forth/talking online etc..

The reason these questions are so important is because Petraeus retired (General in Army) and was made the Head of the CIA.

Benghazi WAS a CIA outpost as well as a Embassy outpost for eastern Libya.

Benghazi also had alot of Al Quieda type groups that were bent on striking the U.S.

Did one (or more) of our Intelligence Organizations trace information from the captured terrorists computors back to the girlfriend and/or straight to Petraeus' laptop?

This could rock our CIA & Military security complex if there's more to this...and I believe there is.

Nobody admits to an affair WHILE resigning, they resign THEN admit way later (if ever) of the affair. Most just state "they want to spend more time with their family", and thats thats.