A federal judge sentenced a Gillette man to 45 years in prison for two counts of production of child pornography, according to court records.

Chief U.S. District Court Judge Nancy Freudenthal handed down the sentences to be served concurrently, or at the same time, to Charles Mathisen in Cheyenne on Wednesday.

In August, Mathisen, 64, pleaded guilty to two counts of production of child pornography, with one offense occurring on April 25, 2014, and the other offense occurring on Oct. 24, 2015..

In exchange for the plea, prosecutors agreed to drop five other counts of child pornography production and two counts of possession of child pornography.

Freudenthal recommended to the U.S. Bureau of Prisons that Mathisen be placed in facilities in either Tucson, Ariz., or Petersburg, Va., for treatment and to protect him from being preyed upon by other inmates.

And while it may seem like piling on, the judge ordered Mathisen to follow these among many rules upon release from custody: be on lifetime probation, register as a sex offender, not possess firearms, submit to mandatory drug testing, not have a computer or internet access without the approval of his probation officers, complete sex offender and substance abuse treatment programs, and work full time.

In June, Mathisen initially was charged with one count of possession of child pornography in a criminal complaint.

On July 20, the federal grand jury handed up the indictment with the two counts of possession and seven counts of production of child pornography.

The indictment says the alleged crimes happened from January 2013 to June 2016.

The case began in May 2016 when the Gillette Police Department began the investigation of a sexual assault of a prepubescent girl, according to the criminal complaint filed by a Gillette police officer.

Police executed an arrest warrant for Mathisen on a charge of first-degree sexual abuse of a minor.

Police also executed a search warrant on his residence. Police seized a computer, digital camera and other electronic devices.

The officer analyzed images and found Mathisen had photographed and made video files of the girl while he was assaulting her, according to the affidavit.
Mathisen also admitted to detectives he used a camera to photograph and video the girl.

In January, a doctor examined the victim and positively identified her as the girl in the images.

This case was investigated by the Wyoming Division of Criminal Investigation Internet Crimes Against Children Task Force.

The government regards child pornography as a crime of violence because it involves sometimes brutal assaults on children who cannot give consent to sexual activity.