(CNN)-Former Delaware U.S. Senate candidate Christine O'Donnell received news she'd been hoping for late Friday. Cleta Mitchell, an attorney for O’Donnell, confirmed to CNN that a federal probe of her campaign has been closed.
“Just got word US Attorney slammed the door shut on CREW’s baseless complaint against me,” O’Donnell tweeted.
Citizens for Responsibility and Ethics filed a complaint in September 2010 amid allegations that O’Donnell misspent more than $20,000 in campaign funds.
Former staff members for O’Donnell accused the then-candidate of using campaign contributions for personal expenses including meals, gas, and rent. It is illegal to use campaign funds for rent or mortgage payments on a candidate's personal home.
O’Donnell, whose 2010 Senate bid marked her third run for the chamber, admitted to using campaign funds for rent, but reasoned that her house also served as headquarters for her campaign.
And for O’Donnell, the investigation’s conclusion equals vindication.
“The justice system should not be used as a political weapon, and we’re going to keep fighting back,” she tweeted.
The news follows the June dismissal of a illegal coordination complaint filed by the former chairman of the Delaware Republican Party with the Federal Elections Commission. FEC rules restrict campaigns from working with outside political action committees. The complaint accused O’Donnell of violating FEC rules by illegally coordinating with the Tea Party Express after a group of activists staged an event to support her Senate candidacy.
O’Donnell had a possible payback plan for the watchdog group that filed the complaint triggering a federal investigation. “Time now for DOJ to investigate CREW!” she tweeted.
CREW had a response of its own to the FEC's action.
Executive Director Melanie Sloan fired back in a statement posted on the group's website Saturday. "If in fact, it is true, as Ms. O’Donnell claims, that the Department of Justice has declined to prosecute her, Ms. O’Donnell joins the ranks of scandal-ridden politicians the Justice Department’s Public Integrity Section has allowed to skate by, despite evidence of criminal wrongdoing," she said.
The U.S. attorney's office in Delaware has not responded to a request for comment.
O'Donnell's former campaign manager Matthew Moran responded Sunday to Sloan's comments describing her as a "shameless fool" who could face further repercussions.
- CNN Senior Producer Kevin Bohn contributed to this report.