A former Stanford University swimmer who raced in the 2012 US Olympic trials has been charged with raping an intoxicated, unconscious woman on the school’s campus.

The San Jose Mercury News reports Brock Allen Turner was charged Tuesday with five felony counts on suspicion of attempted rape and penetration with a foreign object.

“She was lying on the ground unconscious, not moving,” Deputy District Attorney Alaleh Kianerci told the San Francisco Chronicle of the alleged victim, who was not a student at the university.

Prosecutors say the attack happened Jan. 18. Two men riding bikes on campus saw an unconscious woman on the ground with a man on top of her.

Turner ran away, but the two bikers chased him down and held him until police arrived.

Kainerci praised the Good Samaritans and said they acted because what they saw “shocked their conscience.”

Stanford spokeswoman Lisa Lapin said Turner, a 19-year-old freshman from Dayton, Ohio, voluntarily withdrew from the university on Tuesday. Turner is barred from campus.

“Matters like this the university takes seriously,” Lapin told the Chronicle. “The university has launched its own investigation, in addition to and separate from the law enforcement investigation.”

Turner faces being placed on the USA Swimming Banned for Life list because of his arrest in a sex felony. Turner was a three-time All-American high school swimmer.

Prosecutors declined to reveal details about the victim and said only she was attending an on-campus party.

Turner has been released on $150,000 bail.