A U.S. federal judge has declared a mistrial in the case of former Senator and one-time Democratic presidential candidate John Edwards, who was charged with misusing a million dollar campaign fund to hide his affair with a mistress.

The judge in Greensboro, North Carolina made his decision after the jury found Edwards not guilty on one count, but deadlocked on five other counts.

The Justice Department must now decide whether to retry the case.

Edwards emerged from the courthouse, surrounded by his parents and daughter, to again proclaim his innocence and thank the jury. But he said he did an “awful, awful lot that was wrong.” Edwards said he is the only one responsible for his sins.

After deliberating for more than a week, the jury acquitted Edwards of charges that he misused a donation from elderly bank heiress Bunny Mellon. But the panel was unable to reach verdicts on five other counts. They include breaking federal campaign finance laws and accepting contributions that exceed the $2,300 limit from individual donors.

Edwards' lawyers argued that their client did not knowingly break the law. They also said the money from Mellon and another wealthy donor, the late Texas lawyer Fred Baron, were gifts and not campaign contributions.

Prosecutors contended that Edwards used the money to hide his pregnant mistress from the public, while he ran for the presidency in 2008. His wife was ill with breast cancer during the campaign. She died in 2010.

Edwards was a U.S. Senator from North Carolina from 1989 to 2005. He was also the Democratic vice-presidential nominee in 2004.