Greg A. Voegtlin, 44, was convicted on three counts of aggravated criminal sexual abuse, according to the report.
Last year, Charles B. Pelkie, spokesman for Will County State's Attorney James Glasgow, said the victim was first abused in May 2003, when she was just 14 years old.
Aggravated criminal sexual abuse is a Class 2 felony that carries a sentence of three to seven years upon conviction.
Voegtlin is scheduled to be sentenced July 12. His punishment could range from probation to 21 years in prison, according to the Chicago Sun-Times.