GLASFORD, Ill. – A central Illinois grade school principal was charged in the alleged rape of a 20-year-old woman at a party near his home last weekend, authorities said.

John C. Walker, 42, principal of Illini Bluffs Elementary School, was charged Monday with aggravated criminal sexual assault, a felony that carries a sentence of up to 15 years in prison.

The woman, a 2005 graduate of Illini Bluffs High School, told authorities she felt sick and went to a bedroom to lie down during a party Saturday night at a home in Walker’s neighborhood, Peoria County Sheriff Mike McCoy said Tuesday. She claimed that Walker followed her into the house a few minutes later and forced her to have sex, McCoy said.

School officials suspended Walker with pay Monday from his job at the 473-student grade school in Glasford, about 15 miles southwest of Peoria.

“It took us by surprise. We haven’t even talked to him yet,” school board president Ross Fink said before a school board meeting Monday night.

Walker’s attorney, Kerry Cordis, was out of the office Tuesday and unavailable for comment, his secretary said. Walker did not immediately return a call for comment left Tuesday at his home.

Walker, who is married with four young children, posted $7,500 bail and was released from jail Monday. A preliminary hearing is scheduled for Aug. 9.

His arrest is the second this year involving staff in the district of about 1,000 students.

Ian McDonald, 31, resigned as a high school teacher and boys varsity basketball coach in March after being charged with sexual assault stemming from an alleged seven-month relationship with a student. McDonald remains in Peoria County Jail and is scheduled to appear in court again on Aug. 17.