Edwards' former mistress granted immunity Democratic presidential hopeful Sen. John Edwards (D-NC) addresses supporters at a campaign stop in Des Moines, Iowa on January 2, 2008. Iowa holds their presidential caucus on January 3. GREENSBORO, N.C., March 15 (UPI) -- Federal prosecutors Thursday granted immunity to the former mistress of former U.S. Sen. John Edwards, D-N.C., in his trial on campaign finance law violations. Rielle Hunter cannot face criminal charges for anything she says during Edwards' trial, WRAL, Raleigh, reported. Edwards, the 2004 Democratic vice presidential nominee, faces six counts of criminal violations of campaign finance law for using almost $1 million in contributions from two donors to hide Hunter, who was pregnant with his child during his 2008 campaign for the Democratic presidential nomination. He has pleaded not guilty. Prosecutors say Hunter may be asked to testify in the trial, for which jury selection is scheduled to begin April 12. U.S. District Court Judge Catherine C. Eagles said Thursday attorneys Allison O. Van Laningham and Alan Duncan can represent Edwards at trial, but they will not be allowed to cross-examine Hunter if she testifies, the Greensboro News-Record reported.