ASHLAND, Ky. — A federal inmate at the Big Sandy federal prison has been indicted for three counts of assaulting correctional officers at the prison.

Daviian Dwane Roberts, 35, who is now serving a 12.5-year sentence on federal weapons charges in the federal supermax prison in Florence, Col., is accused of assaulting three corrections officers with a weapon last March. The charges could add up to 20 years to his sentence.

No hearings have yet been set in the case.