A Mille Lacs County sheriff's deputy is charged with criminal sexual conduct in a case involving four boys he took fishing while volunteering at the Lutheran Island Camp in Otter Tail County.

Aaron Joseph Heuer, 29, of Isle, Minn., was charged Tuesday in Otter Tail County District Court with four counts of first-degree criminal sexual conduct and four counts of second-degree criminal sexual conduct.

According to the criminal complaint, Heuer was volunteering as a fishing guide at the camp in Henning, Minn., when he allegedly touched four boys, ages 8 to 10, inappropriately and instructed them to have sexual contact with him. Additional incidents allegedly occurred with two of the boys on a separate fishing trip in Aitkin County that was not connected to the camp, according to a preliminary investigation by the Bureau of Criminal Apprehension.

Investigators believe that Heuer knew all of the victims before the alleged incidents.

Heuer, who has worked for the Mille Lacs County Sheriff's Office for six years, was placed on administrative leave. He was being held in the Otter Tail County Jail.

Mary Lynn Smith