ALASKA — Roger Shoffstall, a 75-year-old telecom company owner serving a three-year federal prison sentence for felony tax evasion, sent two documents on Thursday asserting that he is a sovereign citizen of the United States. Shoffstall is incarcerated in an Alaska federal prison.

At the beginning of his prison sentence, a guard caught Shoffstall running his company, Summit Telephone, from behind bars and revoked his telephone privileges.

According to the FBI, sovereign citizens are individuals who believe that although they live in the U.S., they are separate or "sovereign" from the United States. The FBI categorizes the extremist version of the sovereign citizen movement as domestic terrorism.

As a convicted felon, Shoffstall cannot serve on a federal jury and is not allowed to own a gun. He also does not receive an annual Permanent Fund dividend check.

Shoffstall was convicted of felony tax evasion and began serving his three-year sentence at the federal facility in Alaska. The sovereign citizen assertion, made by filing two documents, adds a new development to his case. Sovereign citizens have drawn attention from federal law enforcement because of the domestic terrorism designation applied by the FBI to the movement's extremist wing.

Summit Telephone, the company Shoffstall owned and operated before his incarceration, was at the center of the conduct that led to his telephone privileges being revoked inside the prison. The loss of those privileges came after a guard discovered he was continuing to run the business from his cell.