Police at the University of California, Berkeley said that a female student was sexually assaulted near campus early Thursday morning.
The assault is thought to have occurred in a cooperative housing facility around midnight, and was reported at 4:45 p.m. later that day.
The victim knew her attacker, according to police.
The case remains under investigation and further details were not immediately available.
Roughly 80 percent of sexual assaults and rapes are perpetrated by someone known to the survivor, according to police, and on college campuses roughly 90 percent of survivors know their attackers.
Police said that if you are sexually assaulted and you wish to file a police report, do not shower or wash any clothing worn during the assault.