A senior adviser to former mayor and alumnus Vincent Gray was sentenced to six months in prison Tuesday for obstructing the federal investigation into Gray’s 2010 mayoral campaign finances.

Vernon Hawkins, 77, pleaded guilty to giving a false statement to the investigators in August 2013 over telling one of Gray’s aides to leave town to avoid the investigation, The Washington Post reported Tuesday.

Eight Gray supporters were prosecuted because of their involvement in the illegal fund that propped up Gray’s 2010 mayoral bid. Jeffrey Thompson and Jeanne Clark Harris also pleaded guilty to funding and coordinating the $653,000 in extra campaign funds.

U.S. District Judge Colleen Kollar-Kotelly told The Washington Post that Hawkins “stepped to the dark side” when he “participated in the corruption of a fair election process.”

“You should have had more respect for the voters of this city to elect a mayor of their choosing without corrupting the process,” she said to Hawkins.

The federal prosecutors determined they would not make any charges in the case with the evidence from the years-long federal investigation.