WASHINGTON - The Justice Department has decided not to charge David Petraeus' mistress, Paula Broadwell, with cyberstalking as part of its investigation into an e-mail scandal that led to the resignation of the CIA director and storied general.

Broadwell's attorney, Robert Muse, gave the Associated Press a letter from U.S. Attorney Robert O'Neill that said no federal charges would be brought in Florida related to "alleged acts of cyberstalking."

Petraeus resigned as CIA director in November after acknowledging the extramarital affair, which was exposed after Broadwell e-mailed socialite Jill Kelley, allegedly warning Kelley to stay away from Petraeus and Gen. John Allen, the U.S. commander in Afghanistan.

Kelley reported the e-mails to the FBI, triggering an investigation that led the FBI to Kelley's e-mails to the married Allen, who is now under investigation by the Pentagon's inspector general.

"The decision on whether to bring a prosecution is always a serious matter, and one that should never be undertaken without the most thoughtful deliberation," said Justice Department spokesman William C. Daniels. "After applying relevant case law to the particular facts of this case, the United States Attorney's Office for the Middle District of Florida has decided not to pursue a federal case regarding the alleged acts of 'cyberstalking' involving Paula Broadwell."

A spokesman for Broadwell said that she and her family were "pleased with this decision and pleased that this is resolved."

Her attorney has not been notified that she is the subject or target of any other Justice Department investigation.

Broadwell, Petraeus' biographer and a reserve Army officer, is being investigated by the Pentagon for allegedly mishandling classified information. FBI investigators found a "substantial amount" of material marked classified at her home.

Petraeus and Broadwell said their romantic relationship began only after he retired from the military and started at the CIA.