A state prison inmate was charged Tuesday by a federal grand jury in Scranton with threatening to kill a Monroe County judge, according to the U.S. District Attorney's office.

Devon Williams, 24, allegedly mailed a letter in January 2014 from the State Correctional Institution in Albion to the Monroe County courthouse threatening to injure and kill the chief Common Pleas judge.If convicted of the charge, Williams faces up to five years in prison and a $250,000 fine.The U.S. Postal Inspection Service and state police conducted the investigation.Assistant U.S. Attorney Francis P. Sempa is prosecuting the case.