Lake Park High School District let go of its football coach Thursday after an investigation into how a convicted sex offender was able to serve as a volunteer coach on the team.

As reported by the Chicago Tribune, Chris Roll did not do a criminal background check procedure on his volunteer coach, which is required by the school district. Roll also “directed an assistant coach to remove the volunteer coach” from names that would go through background checks, according to a statement obtained by the Chicago Tribune.

Roll might have lost his position as football coach, but he will still be a teacher in the school district. He returns to his teaching job Friday.

Frank Battaglia, 72, served as the volunteer coach. He pleaded guilty to aggravated criminal sexual abuse in 1992. His victim was between the ages of 13 and 16, according to court documents obtained by the Chicago Tribune.