Patricia Esparza, 39, allegedly identified Gonzalo Ramirez to her ex-boyfriend in 1995 as the man who had raped her in her dorm room at Pomona College in Claremont, Calif., the Los Angeles Times reported.
Prosecutors say Gianni Anthony Van killed Ramirez and dumped the body in Irvine.
A judge revoked Esparza's $300,000 bail Thursday.
Esparza was offered a plea agreement that would have required her to serve three years for involuntary manslaughter, Scott Simmons, a senior deputy district attorney in Orange County, said.
Esparza, who says she identified Ramirez for Van not realizing he would be killed, and then hid his involvement from authorities because she feared him, pleaded not guilty.
"This is an incredible injustice," Esparza's husband, Jorge Mancillas, said. "I guess in Orange County it doesn't count to be innocent."
Van, Shannon Gries and Diane Tran are also charged in the case and entered not guilty pleas Thursday.
Kody Tran, another suspect, was killed last year in a shootout with police.
Esparza, who came to the United States from Mexico as a child, won a scholarship to Phillips Exeter Academy, a boarding school in New Hampshire, and went on to Pomona. While she says she and Van had broken up at the time Ramirez was killed, they later married and divorced.
Mancillas and Esparza both teach at Webster University in Geneva, where she is an assistant professor of psychology, and live in a small town across the border in France. Esparza was arrested last year when she flew to St. Louis for a conference.
Esparza did not report the rape to police, although she visited a school nurse and was given morning-after birth control. She said she felt guilty at the time and did not want her family to know she had met Ramirez in a nightclub during a weekend at home and accepted a ride back to school with him.