SIOUX FALLS - A South Dakota State Penitentiary inmate accused of threatening to hurt a federal judge has been ordered to undergo mental tests.

Both federal prosecutors and Christopher James Austad's lawyer requested the evaluations. U.S. Magistrate John Simko granted the motions.

Austad, 25, has filed a notice in federal court that he intends to use an insanity defense.

Austad was ordered to take the mental exam in a Bureau of Prisons facility. Simko said a report on the tests must address whether Austad is mentally competent to understand the nature and consequences of the proceedings or assist in his own defense.

Also, the report must discuss whether Austad knew that what he's alleged to have done was wrong, the magistrate's order said.

Austad and another penitentiary inmate, Jason Paul Wood, 25, were indicted Aug. 30 for mailing threatening communications to U.S. District Judge Ann Aiken of Eugene, Ore.

The written communications, sent by Wood on June 25 and July 19 and by Austad on July 15, included threats to injure her, according to the indictment.

The maximum punishment on each count is 10 years in prison.

Austad already must serve a seven-year federal sentence after he pleaded guilty to threatening another federal judge and the president. He mailed a letter March 27, 2006, to U.S. District Judge Richard Battey of Rapid City in which he threatened to injure the judge and kill President Bush, according to court documents.