Transcript for David Petraeus Scandal: Truth Behind Resignation, Paula Broadwell
The latest on bombshell that's still reverberating through washington. More details about the shocking scandal that cost the head of the can cia his job. David kerley has new information about david petraeus' extramarital affair came to light. Reporter: We're learning stung details about this scandal. It was an affair between petraeus and his biographer paula broadwell. Broad we'll had access to petraeus. I they trusted me. I got to know his family and e his mentors. Reporter: Confirmed as cia director more than a year ago. Several sources tell abc news that it was an e-mail that unravelled the affair. Couple of months ago, a woman in the tampa area, with a association with david petraeus, received a strange and harassing e-mail which launched the investigation. The e-mail was traced back to the computer of paula broadwell. But what agents found instead of a account were salacious e-mails between petraeus and broadwell. There had been rumors between him and broadwell for some time. But, frankly, I didn't believe them and neither did just about anybody else I knew. He just didn't seem the type. Reporter: Martha raddatz reports that some of his afghanistan staff worried about how it looked with broad spending so much time with him. An official tells abc news that it was just tuesday evening that the head of national intelligence was told. Thursday at the white house, petraeus offered his resignation to the president, who waited 24 hours to accept. So shocking because petraeus himself had been critical of officers guilty of infidelity. He spoke of them in this tone of contempt that they had exchangesed in this type of behavior. This morning, he has no plans to start the investigation. David, so many people are questioning the timing of this, coming just days after the election, if the fbi had been investigating the situation for months, how is it the white house and congress were both left in the dark. Reporter: Peter king one raising questions. No response directly from the white house yet. Investigators for the intelligence community will say, listen, this wasn't a matter of national securit what they found was a personnel issue. All right, I have a feeling that this story is far from over. David, thank you so much dan? This scandal has derailed two promising careers. Paula broadwell is a life long overachiever, she graduated from harvard, a triathlete and mother of two. Reporter: I spoke to friends and colleagues who knew paula broadwell. They called her the star of her generation at west point. Technology can't solve all of the problems. Featured in mentary about weapons system. Military smarts and enviable physique, friends said that she was devoted to the cause of wounded warriors. Making this ironic that this scandal comes on veterans day weekend. Takes the time to help somebody like me. There's not much time for indiscretions. Reporter: David bixler, a wounded warrior knows paula through a charity foundation. Last week, broadwell was to skydive but donated it to bixler. He questions these latest allegation and I have some serious questions about who's connecting these dots. Reporter: Some of her colleagues say that she's someone to be admired. She's reversed the cause of young women in the military. Those who know her said that she was facebook all the time. On friday morning, her 40th birthday, she posted an apost about mortality and exercise. A likely clue that she had no ideas that hours later her entire profile would be wiped. Not sure when her husband learned about this affair. Broadwell was celebrate to her WHOth BIRTHDAY AT A DINNER AT Washington. Herusband called and canceled the event late friday.
This transcript has been automatically generated and may not be 100% accurate.