A former driver for D.C. Mayor Vincent Gray pleaded guilty to conspiracy in connection with Gray's 2010 campaign.
Mark Long pleaded guilty to one count in D.C. Superior Court late Friday morning.
Long, a former D.C. Council candidate, served as the driver for Gray during his 2010 campaign and allegedly drove the mayor to secret meetings.
On Thursday, Long become the sixth person to be charged with a crime related to illegal funding of that campaign.
“Mark Long’s guilty plea is further evidence that this 2010 mayoral campaign was rife with corruption," U.S. Attorney for the District of Columbia Ronald Machen said. “Our work continues.”
A charging document says Long was paid by a public-relations firm to serve as Gray's driver and that those payments weren't reported to campaign-finance officials. It also says Long was involved in a scheme to pay another candidate to drop out of the race and endorse Gray. The document does not identify Gray by name, but prosecutors have previously named him in court in related cases.
Long's sentencing is scheduled for October.
He is cooperating with investigators looking into the scandal, but it is still unknown what information he may be providing.