A federal investigation into a Russian file sharing program for exchanging child pornography ended in a Greenfield home where police say a 26-year-old Milwaukee man produced and exchanged child pornography.

Justin M. Peterson was charged in Milwaukee County Circuit Court Friday with one count of first-degree sexual assault of a child less than 13 years old and four counts of possession of child pornography. If convicted, he faces up to 100 years in prison and $400,000 in fines.

According to the criminal complaint:

The U.S. Department of Homeland Security was investigating a Russian file sharing system where people were exchanging child pornography, which led them to a suspect in Arizona who was exchanging files on the program. While looking into that suspect, federal investigators found files that traced back to Peterson’s emails sent to the Arizona man’s computer.

The IP address the files were connected with was traced to a home on South Honey Creek Drive, the complaint states. Officers went to the house and talked with a woman who lived there; said Peterson was a friend who had moved in after breaking up with his girlfriend and needed a place to stay.

While living in the home, the woman said Peterson would use her Internet and watched her children.

Several of the child pornography images and videos showed a sleeping young girl in partial states of undress, which investigators discovered was the woman’s 8-year-old daughter.

The girl said she would watch television in Peterson’s room and fall asleep. She didn’t remember pictures, but said she did remember one time waking up in different clothes.

Investigators looked further into Peterson’s files, the complaint states, and discovered more child pornography of pre-pubescent boys.

Peterson is scheduled to make his initial appearance in court Monday.