WASHINGTON (AP) — A former D.C. Council candidate who served as driver for District of Columbia Mayor Vincent Gray during his 2010 campaign has pleaded guilty to conspiring to violate campaign finance laws.

Prosecutors say Mark Long acknowledged Friday as part of a plea deal that he knew payments made to him were being concealed from officials. He faces one to 12 months in prison or probation.

Long, who unsuccessfully ran for a council seat in 2008, is the sixth person to plead guilty to charges involving the 2010 election. An investigation after Gray’s election uncovered a $653,000 slush fund never reported to campaign-finance officials that helped Gray get elected. Gray has not been charged with a crime and has denied all wrongdoing.

Long’s attorney did not immediately return a message seeking comment.

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