A former Mille Lacs County sheriff's deputy pleaded guilty Friday to molesting young boys at an Otter Tail County summer camp where he was a volunteer.

Aaron Joseph Heuer faces up to 33 years in prison after pleading guilty to four counts of first-degree criminal sexual conduct and one count of second-degree criminal sexual conduct against five different victims, according to the Minnesota Department of Public Safety.

The charges stem from June 2013, when Heuer was volunteering as a fishing guide at Lutheran Island Camp in Henning. He pleaded guilty to sexual contact with young boys at the camp, all between the ages of 8 and 10. Investigators believe he knew the children prior to the incidents, which included a separate fishing trip in Aitkin County that was unrelated to the camp.

Heuer, a resident of Isle, also pleaded guilty to one count of criminal sexual conduct in Mille Lacs County. The plea agreement calls for a sentence of 396 months in prison. His sentencing is scheduled for May 8 in Otter Tail County District Court.