Pierce O'Donnell has agreed to serve six months in federal prison, pay a $20,000 fine and do 200 hours of community service for masking contributions to John Edwards in 2004. In a plea agreement with prosecutors, O'Donnell admitted to asking 10 people to each make donations of $2,000, which he then reimbursed.O'Donnell, 64, who was a lead plaintiff's attorney for Katrina flood victims suing the U.S. government, previously pleaded no contest in 2006 to charges of using a false name in making political contributions in the 2001 mayoral campaign of James K. Hahn.