CHEYENNE, Wyo. (AP) — A federal appeals court for the second time has denied a Casper man's efforts to challenge his child pornography conviction.

The 10th Circuit Court of Appeals in Denver on Tuesday dismissed an appeal filed by Nathaniel Solon.

Solon was convicted in 2008 and sentenced to six years in prison. He went on supervised release this January.

Solon has maintained that a computer virus infected his computer with illegal images of children.

Solon also has argued that U.S. District Judge Clarence Brimmer of Cheyenne undermined his defense by leaving the courtroom during closing arguments and by belittling a defense witness.

Tuesday's ruling marks the second time the Denver court has refused to overturn Solon's conviction. The U.S. Supreme Court refused to hear his case in 2010.