Kelley — who lives in a waterfront mansion along one of Tampa's toniest streets — had told an FBI agent that she had received threatening emails telling her to stay away from Petraeus, who once commanded Central Command at MacDill Air Force Base in Tampa. Petraeus got to know Kelley through parties and events around Tampa.

Agents tracked the emails to Petraeus biographer Paula Broadwell, who was having an affair with the former general.

During the investigation, officials also discovered that Kelley had exchanged numerous emails with Gen. John Allen when he was in charge of Central Command. The Pentagon is investigating potentially "inappropriate" correspondence between Kelley and the four-star general, who is the top U.S. and NATO