(HO/HO/AFP/Getty Images)

Just days after he was indicted on federal charges of using illegal campaign donations to conceal his mistress from voters, the U.S. Marshals Service on Wednesday released the mugshots of former Sen. John Edwards (D-N.C.).

Edwards, who was the 2004 Democratic vice presidential nominee, pleaded not guilty to the charges. The six-count indictment triggered immediate criticism from a range of campaign finance and legal experts, who said the government’s case is unprecedented and appears weak. They questioned whether it would survive the fierce defense being mounted by Edwards’s lawyers, who contend that his actions did not constitute a crime.

The former senator has been the subject of a federal investigation since at least early 2009, when Edwards confirmed that political groups linked to him were among the potential targets of a probe in the aftermath of his affair with former campaign aide and videographer Rielle Hunter. In January 2010, after months of denials, Edwards admitted to being the father of Hunter’s daughter, Quinn. Shortly afterwards, Edwards separated from his wife, Elizabeth Edwards, who died after a long bout with cancer in December.