TULSA, Oklahoma - A former Union Public Schools teacher was sentenced to 13 years in federal prison for receiving child pornography.

James Russell Wilson was also sentenced to 20 years of supervised release following the prison time.

According to court documents, from October 2014 to around December 2014, Wilson found an Instagram profile of a 12-year-old girl and started sending messages to her on a different program.

Documents say he continued chat with the girl and requested increasingly more revealing and ultimately sexual photos.

Documents also say Wilson tried to get the child to expose herself and perform sexual acts. They also say the former teacher sent explicit pictures of himself to the girl.

Wilson, according to the documents, eventually convinced the 12 year old to send explicit photos of herself.

Investigators say the girl's mother discovered the photos and messages on her daughter's iPod in December 2014, and called the Manitoba Royal Canadian Mounted Police.

Investigators say they found 235 photos and videos of "infants, toddlers and children under the age of 18" engaged in "explicit sexual activity."