With his father at his side, Brock Allen Turner, 19, entered his plea in a Palo Alto courthouse. Afterward his attorney, Michael W. Armstrong, declined to comment on the case to The Times.
Turner was arrested Jan. 18 after two men riding bicycles on campus about 1 a.m. spotted him on top of an unconscious woman, according to the police report filed with the criminal complaint.
Turner and the woman, who is not a Stanford student, both attended the same fraternity party that evening. Turner is not a member of a fraternity, university spokeswoman Lisa Lapin told The Times.
In an interview with police, Turner said he arrived at the party about 11 p.m. and kissed a few women before hooking up with the woman who was later found unconscious, according to the police report. He couldn't recall her name.
The two witnesses said that after he was spotted, Turner rose and fled. The two men eventually chased him down and restrained him until police arrived.
A campus police officer found the woman lying on her side behind a Dumpster near an on-campus fraternity. Unconscious but breathing, she was taken to a hospital.
Turner was booked in the San Jose Main Jail and later released after posting $150,000 bail.
Santa Clara County prosecutors charged Turner with five felonies, including rape of an unconscious person, rape of an intoxicated person, assault with the intent to commit rape, sexual penetration of an intoxicated person, and sexual penetration of an unconscious person, according to the criminal complaint.
Turner voluntarily withdrew from the university last week, Lapin said. He's not allowed to re-register for classes and is barred from setting foot on campus, she said.
The investigation into the incident was conducted by the Stanford University Department of Public Safety, which turned over its findings to prosecutors.
Turner was a freshman at Stanford. He swam freestyle and backstroke for the Cardinal, according to the university's online athletic roster. His profile has since been taken down.
Turner's next court appearance is scheduled for March 30.