(KCEN) -- We're learning more about the departure of CIA Director David Petraeus.
The retired general resigned after publicly admitting to an extramarital affair.
And for the nation's top spy it was a breach of trust the general himself called unacceptable.
The woman who he was involved with was author Paula Broadwell.
Broadwell an Army Reserve Officer had close access to the CIA Director and federal agents are investigating whether she had access to his emails or computer.
NBC Analyst Ret. Colonel Jack Jacobs says, "My understanding is the FBI's investigation about what took place on computers there, did not necessarily, was not necessarily focused on him. They came by the information by accident."
In his resignation letter the retired four-star general revealed he had "showed extremely poor judgment by engaging in an extramarital affair."
General Petraeus is not under investigation and the inquiry will likely not result in criminal charges.
Petraeus was the man who turned around the wars in Iraq and Afghanistan.