The woman, a 23-year-old University of Cincinnati student, woke up during the attack and fought back but could not get away, said Hamilton County prosecutor Seth Tieger.
Dexter Ford, 52, was also charged Tuesday with felonious assault because he knew he was HIV-positive, Tieger told The Cincinnati Enquirer. Police said Ford told them that he is HIV positive, and Hamilton County Municipal Judge Fanon Rucker ordered Ford to be tested for venereal diseases. It was not clear if the woman has been tested.
Ford was indicted by a grand jury on two charges of rape, attempted rape, kidnapping and felonious assault. He faces as many as 46 years in prison if convicted on all counts.
Ford's attorney, Jeff Adams, said the case will center on the woman's state.
"How is he to know she is sleepwalking, if it's a dream 'yes' or a real 'yes?"' Adams said.
The prosecutor said the woman did not consent to sex, and anyone seeing her in her sleepwalking state would have known that something was wrong. "It's not like she was carrying on a normal conversation," Tieger said.
The woman was walking near Interstate 71 at about 3:30 a.m. Nov. 8, police said. Two passing motorists phoned police to report that a man was on top of a woman.
It was not the first time the woman, who has epilepsy, has wandered outside her home while sleepwalking, Tieger said.