Billings resident David Gene Norton, who admitted receiving child pornography on his computer, will spend more than 13 years in federal prison.

Although Norton, 47, denied allegations that he also sexually abused a 15-year-old girl, the judge ruled that he was responsible for a pattern of abuse on two occasions. Norton was never charged or convicted of the offenses, but the finding increased the upper range of the sentencing guideline from eight years to 14 years.

Senior U.S. District Judge Jack Shanstrom on Wednesday sentenced Norton to 13 years and four months, which was near the top of the range. He also ordered a lifetime of supervised release. The judge dismissed a second count of possession of child porn.

Norton pleaded guilty in June to receiving child porn.

Assistant U.S. Attorney Marcia Hurd said Yellowstone County sheriff’s deputies responded in December to a report that a 15-year-old girl had been sexually assaulted at Norton’s Shepherd residence. During the investigation, the teen reported that Norton liked to view child porn on his home computers.

A search of two computers seized found 230 child porn images, including images of prepubescent children and children engaged in sadistic or masochistic abuse.

During the sentencing hearing, the victim testified that Norton had inappropriate sexual contact with her. She admitted that she had lied about small things to avoid getting into trouble but that she wasn’t lying about Norton or in her testimony.

Assistant federal defender Dave Merchant argued that there was no credible evidence Norton had sexually abused the victim and that she could not be believed because of her admitted lying. A six-year sentence was sufficient punishment, he said.

Norton testified he was just surfing and “goofing” with the Internet, clicking on Web sites.